MODERN 
PULP  and  PAPER 
MAKING 

A  Practical  Treatise 


BY 

G.  S.  WITHAM,  SR. 

manager  of  mills 

Union  Bag  Paper  Corporation,  Hudson  Falls,  N.  Y. 


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1920 

BOOK  DEPARTMENT 

The  CHEMICAL  CATALOG  COMPANY,  Inc. 

One  Madison  Avenue 


New  York,  U.  S.  A. 


Copyright,  1920,  by 

The  Chemical  Catalog  Company,  Inc 
All  Rights  Reserved 


* 


\ 


Press  of  J.  J.  Little  &  Ives  Co-i  New  York 


CONTENTS 


CHAPTER  PAGE 

I.  Processes  by  Which  Pulp  is  Produced  ....  i 

II.  Materials  from  Which  Pulp  is  Produced  ...  5 

III.  Varieties  of  Paper . 40 

IV.  The  Saw  Mill . 54 

V.  The  Wood  Room . 72 

VI.  The  Sulphite  Mill . 95 

VII.  The  Acid  Plant . 126 

VIII.  The  Soda  Process . 146 

IX.  The  Sulphate  Process . 176 

X.  The  Ground  Wood  Mill . 184 

XI.  Bleaching . .  .  ,  .  .  .  202 

XII.  The  Beater  Room . .  ,  .  .  .  .  221 

XIII.  The  Machine  Room  281 

XIV.  The  Finishing  Room . ,378 

XV.  General  Design  OF  Pulp  AND  Paper  Plants  .  .  .  .  388 

XVI.  The  Power  Plant . 4ii 

XVII.  Testing  OF  Paper  AND  Paper  Materials . 462 

XVUI.  Paper  Defects;  Their  Cause  and  Cure  ....  501 

XIX.  Personnel . 5o8 

XX.  Useful  Data  and  Tables . 544 

XXL  Index . . 


Preface. 


During  thirty-seven  years  of  experience  in  the  pulp  and  paper 
industry  the  author  has  frequently  and  repeatedly  felt  the  need 
of  a  practical  work  on  the  manufacture  of  pulp  and  paper, ^  as 
carried  on  in  America,  that  would  not  be  so  abstruse  and  technical 
as  to  be  beyond  the  grasp  of  the  average  papermaker,  and  which 
at  the  same  time  would  not  merely  skim  the  surface  of  the  various 
subdivisions  of  the  art. 

In  the  present  volume  an  attempt  has  been  made  to  descnbe 
the  equipment  and  processes  actually  used  in  pulp  ^  and  papei 
plants  on  this  continent  today,  giving  such  practical  information 
as  would  be  of  help  to  men  working  around  these  plants  from 
day  to  day.  It  is  hoped  that  the  present  volume  will  be  useful  to 
practical  papermakers  and,  at  the  same  time,  that  it  may  possibly 
be  of  service  to  technical  men  not  intimately  in  touch^  with  the 
pulp  and  paper  industry  and  desiring  to  know  the  salient  facts 

about  it.  •  •  r  • 

No  attempt  has  been  made  to  describe  every  piece  of  equip¬ 
ment  ever  used  in  the  industry.  Neither  has  the  author  attempted 
to  deal  with  the  historical  aspect.  Also,  while  recognizing  I  le 
oreat  importance  of  chemistry  in  connection  with  papermaking, 
no  chemical  considerations  have  been  introduced  which  would  not 
readily  be  comprehended  by  one  with  no  special  knowledge  ot 


It  may  seem  strange  to  some  readers  of  this  book  that  the 
author  has  not  devoted  more  space  to  detailed  information  con¬ 
cerning  bag  paper — with  which  branch  of  the  .n  ^ 

particularly  identified.  In  the  first  place,  relatively  few  of  t  e 
readers  of  this  book  are  likely  to  be  especially  interested  m 
bag  paper,  and  if  overmuch  space  were  devoted  to  this  subjec  ^ 
refdLs  interested  in  other  branches  might  justifiably  feel  that 
their  interests  had  been  neglected.  Of  course,  t  us  i  cu  y 
might  have  been  avoided  by  giving  equally  detailed  attention  to 
every  variety  of  paper,  but  such  a  treatment  would  have  neces¬ 
sitated  a  much  larger  book  and,  consequently,  one  so 
as  to  be  beyond  the  reach  of  many  men  actually  engaged  in  tl  e 
industry.  Moreover,  the  author  has  felt  a  certain  reluc  ance 


PREFACE 


devoting  too  much  space  to  the  particular  branch  of  the  industry 
with  which  he  is  commercially  identified. 

Whenever  the  author  has  made  use  of  ideas  and  experience 
of  others  as  expressed  in  the  literature  serving  the  pulp  and 
paper  field,  he  has  endeavored  to  give  due  credit. 

Thanks  are  due  to  the  many  manufacturers  of  equipment,  who 
have  so  kindly  furnished  material  for  illustrations,  as  well  as 
much  important  information  that  is  incorporated  in  this  book. 
The  author  also  is  much  indebted  to  the  Union  Bag  and  Paper 
Corporation  for  permission  to  use  many  illustrations  taken  in  the 
company’s  plants.  He  is  also  duly  appreciative  of  the  assistance 
rendered  by  Mr.  G.  S.  Witham,  Jr.,  who  has  contributed  many 
useful  hints,  especially  concerning  the  power  plant  chapter ;  by 
Mr.  H.  S.  Ferguson  of  New  York,  who  kindly  checked  all  the 
figures  on  power  consumption,  and  by  Mr.  William  P.  Cutter, 
to  whom  is  due  the  index  at  the  back  of  the  book. 

Finally,  the  author  wishes  to  express  his  grateful  appreciation 
of  the  assistance  rendered  on  behalf  of  the  Publishers  by  Mr. 
Francis  M.  Turner,  Jr.,  Technical  Editor  of  the  Chemical  En¬ 
gineering  Catalog,  who  has  co-operated  with  the  author  through¬ 
out  the  preparation  of  the  manuscript,  covering  a  period  of  nearly 
two  years. 

G.  S.  With  AM,  Sr. 

Hudson  Falls,  New  York. 


MODERN  PULP  AND  PAPER  MAKING 


I.  Processes  by  Which  Pulp  is  Produced. 

Wood  is,  at  the  present  time,  the  raw  material  most  used  in 
the  paper  pulp  industry;  consequently,  the  manufacture  of  wood 
pulps  possesses  the  greatest  inter'Cst  from  a  technical  and  indus¬ 
trial  point  of  view.  The  processes  by  which  rags  and  other 
materials  are  converted  into  pulp  will  be  fully  dealt  with  in  a  later 
cliS-Dtcr 

Wood  is  converted  into  pulp  suitable  for  the  manufacture  of 
paper  by  two  distinct  classes  of  methods.  The  first  class  includes 
the  mechanical  methods  which  produce  mechanical  wood  pu  p 
or  i^round  wood.  The  second  class  includes  the  various  chemical 
methods,  which  produce  chemical  pulp  or  cellulose;  this  class 
comprises  such  methods  as  the  sulphite,  soda,  sulphate  and  Kratt 
processes. 

Mechanical  Process. 

Mechanical  pulp  is  frequently  called  ground  wood  which  name 
simiifies  a  product  consisting  of  wood  pulp  obtained  by  grinding 
wood  into  a  fibrous  condition.  Mechanical  pulps  may  be  divided 
into  two  classes,  ordinary  mechanical  wood  pulp  and  brown  pulps 
or  semi-chemical  pulps  which  are  made  by  subjecting  the  wood  to 
a  slight  steaming  before  grinding.  The  ground  wood  P^o^es^  ^ 
a  very  simple  method  of  manufacture,  as  it  merely  involves  the 
wet  grinding  of  wood  blocks.  The  composition  of  the  mechanical 
pulp^is  practically  identical  with  that  of  the  vvood  itself  h  the 
exception  again  of  the  semi-chemical  pulp,  which,  as  a  result  of 
S  slight  steaming,  has  lost  some  of  the  soluble  resinous  incrus- 

Ground^  woS  made  from  fresh  wood  has  a  distinctive  color 
bearing  on  light  yellow  when  it  is  properly  ground  and  several 
sSdes  li-hter  thmi  when  ground  with  dull  or  hot  stones.  As 
f  matter  of  fact,  by  careful  observation  and  practice,  one  can 
iudee  the  base  of  good  ground  wood,  when  properly  made,  from 
ts  color  If  sap  rot  wood  is  ground  these  fibres  can  be  detected 
o;ing  to  the  fa'ct  that  the  wo^od  is  so  soft  that  ^e  PU^is  o- 
off  in  fine  chunks  and  will  appear  as  such  m  the  pulp  itse  t. 
Made  from  such  material,  the  pulp  will  invariably  dark  bu  y, 
spongy  and  lifeless.  In  addition,  a  lighter  colored  pulp  will  re 


2  MODERN  PULP  AND  PAPER  MAKING 

suit  from  a  wood  that  is  too  dry,  frohi  wliich  the  sap  and  other 
life-giving  bodies  have  been  dried  out. 

The  pulp  produced  by  the  mechanical  process  is  inferior  to 
that  produced  by  the  chemical  processes  and  consequently  it  is 
only  used  in  making  those  kinds  of  paper  where  high  quality  is 
not  demanded  and  price  is  the  chief  consideration,  e.  g.,  in  news¬ 
print,  or  else  in  judicious  combination  with  chemical  pulp,  as 
in  the  manufacture  of  certain  bag  and  wrapping  papers.  Tbe 
inferiority  of  paper  containing  mechanical  pulp  is  due  to  the 
shortness  and  weakness  of  the  fibres,  together  with  the  fact  that 
such  paper  will  quickly  deteriorate  and  turn  yellow  owing  to  the 
action  of  the  atmosphere  on  the  lignins  contained  in  the  wood 
pulp. 

Mechanical  pulp  is,  however,  much  cheaper  to  make  than  any 
other  form  of  paper  pulp.  In  the  first  place,  only  about  two  per 
cent  of  the  raw  material  is  lost,  as  compared  to  fifty  per  cent  or 
more  in  the  chemical  processes.  Secondly,  there  are  no  chemicals 
required.  ^  Finally,  the  equipment  necessary  for  making  mechan¬ 
ical  pulp  is  much  cheaper,  both  as  regards  first  cost  and  mainte¬ 
nance  than  that  required  for  making  chemical  pulp. 

Semi-chemvical  pulp  is  a  variety  of  mechanical  pulp  in  making 
which  the  wood  is  steamed  and  softened  before  being  ground. 
In  this  way  certain  characteristics  are  brought  out  that  make  the 
pulp  more  suitable  for  some  finished  products,  stronger  and  more 
flexible  than  that  produced  by  the  ordinary  mechanical  process. 
Owing  to  the  action  of  the  steam  on  the  wood  the  fibers  are  col¬ 
ored  brown  as  a  result  of  oxidation,  and  this  limits  the  applica¬ 
tion  of  this  kind  of  pulp  to  uses,  such  as  the  making  of  brown 
boards  and  wrapping  paper,  where  this  color  is  not  objectionable. 

Sulphite  Process. 

Sulphite  pulp  is  obtained  by  digesting  wood  chips  with  an  acid 
liquor  at  a  high  temperature  and  pressure.  The  acid  liquor  is 
chemically  known  as  bisulphite  of  lime  liquor'.  This  liquor  is 
prepared  at  the  pulp  mill  in  a  special  plant  known  as  the  Acid 
Plant,  which  will  be  described  in  detail  in  a  subsequent  chapter. 

The  liquor  dissolves  and  removes  all  the  constituents  of  the 
wood  chips  except  the  cellulose,  which  in  impure  form  consti¬ 
tutes  the  unbleached  sulphite  pulp.  When  bleached  this  pulp 
consists  of  practically  pure  cellulose.  The  yield  of  cellulose  will 
vary  from  49  per  cent  to  53  cent  of  the  weight  of  the  prepared 
wood,  depending  upon  the  exact  process  employed.  The  Mit- 
scherlich  process  employing  a  slow  indirect  cook  will  give  the 
highest  yield,  while  the  short,  direct  cook  will  give  the  minimum 
yield. 

Sulphite  pulp  costs  considerably  more  to  make  than  mechanical 
pulp.  In  the  first  place  only  about  50  per  cent  of  the  raw  ma¬ 
terial  is  retained  in  the  finished  product.  Moreover,  much  labor 
and  power  must  be  spent  on  the  preparation  of  the  wood  before 


PROCESSES  BY  WHICH  PULP  IS  PRODUCED  3 

it  reaches  the  digesting  process  proper.  Also,  it  involves  the  up¬ 
keep  of  a  large  chemical  plant  for  making  the  acid  liquor.  Finally, 
the  machinery  is  expensive  both  as  to  first  cost  and  maintenance, 
the  upkeep  being  high  as  the  acid  nature  of  the  process  makes 
for  rapid  deterioration.  The  sulphite  process  requires  about 
1,300  to  1, 500  lbs.  of  coal  per  ton  of  pulp ;  232  lbs.  of  sulphur  ;  300 
lbs.  of  limestone. 

However,  the  greater  length  and  higher  pliability  and  strength 
of  the  sulphite  fibres,  together  with  the  freedom  from  deteriora¬ 
tion  causes  it  to  be  used  instead  of  mechanical  pulp  for  all  except 
the  cheapest  grades  of  paper  in  spite  of  its  higher  cost. 

Soda  Process. 

In  the  soda  process  wood  and  other  fibres  are  digested  in 
various  forms  of  equipment  with  caustic  soda  solution  which  com¬ 
bines  with  the  acid  constituents  of  the  non-fibrous  parts  of  the 
wood,  leaving  pure  cellulose  in  an  insoluble  state,  which  is 
washed  to  free  it  from  the  impurities  that  may  have  been  formed 
during  the  reaction. 

The  soda  process  is  of  general  application  for  many  woods  and 
fibres  that  cannot  readily  be  treated  by  the  sulphite  process.  Or¬ 
dinarily  the  soda,  process  is  used  for  the  reduction  of  short  fibre 
woods  such  as  poplar,  beech,  etc.  Unbleached  soda  pulp  is  used 
in  the  manufacture  of  wrapping  paper  where  color  is  not  a  con¬ 
sideration.  In  the  bleached  state  it  is  used  in  the  manufacture 
of  book,  magazine  and  envelope  papers  where  soft  texture  anc 
bulk  are  the  essential  requisities. 


Sulphate  Process. 

The  term  sulphate  pulp  was  originally  used  to  designate  a 
thoroughly  cooked  pulp  that  could  be  bleached  with  a  reasonable 
amount  of  bleach,  made  by  digesting  wood  chips  with  sodium, 
sulphate  and  sulphide  liquor.  This  pulp  found  application  m  the 
manufacture  of  papers  quite  different  from  those  made  from 
Kraft  pulp.  The  term  Kraft  pulp  was  originally  intended  to  mean 
practically  uncooked  sulphate  pulp  which  was  further  disin¬ 
tegrated  by  means  of  a  kollergang  before  being  put  oiyhe  paper 
machine.  Now,  however,  the  two  terms  sulphate  and  Kraft  have 
gradually  merged  into  each  other  as  a  result  of  the  decreased 
output  of  true  sulphate  pulp  and  the  increased  production  of 
and  demand  for  the  Kraft  pulp. 


Kraft  Process. 
Kraft  pulp 


js.rair  puip  derives  its  name  frorn 
strength,  which  is  its  chief  characteristic.  The  name  Kraft  pulp 
originally  referred  to  a  practically  uncooked  sulphate 
wal  further  worked  up  in  a  kollergang  before  being  put  on  the 
paper  machine.  The  treatment  m  kollergangs  has  been  almost 
Ltirely  abandoned,  at  least  in  America,  the  disintegration  no\^ 


4  MODERN  PULP  AND  PAPER  MAKING 

being  completed  in  the  beaters  and  Jordan  engines.  At  the 
present  time  the  terms  Kraft  and  snlphate  pulp  are  used  prac¬ 
tically  interchangeably. 

Kraft  pulp  is  of  a  dull  brown  shade  when  unbleached  and  it 
is  rarely  bleached  since  the  process  would  require  an  immense 
amount  of  bleach  and  under  no  conditions  would  the  bleached 
pulp  have  the  purity  and  brilliancy  of  bleached  sulphite  pulp. 
Consequently  it  is  used  for  the  manufacture  of  products  where 
color  is  not  a  consideration  and  where  strength  and  ability  to  re¬ 
sist  all  kinds  of  wear  and  tear  is  desired,  as  for  instance  in  wrap¬ 
pings  and  bag  papers. 

The  Kraft  process  is  especially  adaptable  to  the  pulping  of 
long  fibered  resinous  and  non-resinous  woods.  Certain  kinds  of 
wood  that  are  useless  in  the  manufacture  of  sulphite  pulp  are 
adaptable  to  the  Kpft  process.  This  fact,  together  with  the  fact 
that  Kraft  pulp  is  ideal  for  certain  much  used  kinds  of  paper  has 
given  a  great  impetus  to  the  Kraft  branch  of  industry. 

In  the  Kraft  process  several  valuable  by-products  are  formed 
which  have  found  commercial  use.  The  recovery  of  methyl  al¬ 
cohol,  oil  of  turpentine  and  various  resins  is  being  carried  out  on 
a  commercial  scale.  The  lime  sludge  obtained  in  the  causticizing 
of  the  lime  liquor  has  been  successfully  worked  up  into  a  satis¬ 
factory  coating  material.  It  is  only  of  late  that  attention  has 
been  paid  to  the  utilization  of  these  various  by-products,  but  with 
the  increasing  cost  of  raw  materials,  labor,  etc.,  such  economies 
are  rapidly  becoming  essential  in  all  branches  of  the  industry  in 
order  to  meet  the  figures  of  the  competitor. 

So  far  we  have  merely  enumerated  and  briefly  described  the 
general  processes  of  mechanical  and  chemical  treatment  of  raw 
materials  ordinarily  used  for  making  pulp.  Each  of  these  proc¬ 
esses  will  be  the  subject  of  further  and  much  more  detailed  treat¬ 
ment  in  subsequent  individual  chapters.  Besides  the  above  main 
branches  of  pulp  manufacture  there  are  numerous  special  modi¬ 
fications,  such  as  treatment  of  straw,  esparto,  bamboo,  cotton 
linters,  ramie,  bagasse,  etc.  Besides  the  varying  chemical  treat- 
nients  of  the  above  and  other  fibers,  we  have  the  treatment  of  rag, 
rope,  jute  and  waste  paper  stocks,  which  are  more  of  the  nature 
of  cleaning  and  purifying  processes.  The  de-inking  and  re¬ 
pulping  of  waste  papers  on  a  large  scale  has  recently  assumed  a 
position  of  great  importance  and  introduced  many  new  problems 
into  the  industry.  Descriptions  of  these  processes  are  incorpo¬ 
rated  in  the  chapter  on  Materials  of  Pulp. 


II.  Materials  of  Pulp. 

For  the  manufacture  of  paper  vegetable  substances  have  come 
to  be  of  the  greatest  importance  and  the  commercial  value  of  any 
one  vegetable  substance  is  governed  by  the  following : 

1.  The  quantity  of  cellulose  that  the  fibres  contain. 

2.  The  quality  of  this  cellulose. 

3.  The  facility  with  which  the  cellulose  can  be  extracted  from 
the  fibres. 

Cellulose. 

Cellulose  is  a  definite  chemical  compound  with  the  formula 
C9H10O5  almost  always  of  vegetable  orgin  and  always  existing  in 
an  organized  condition,  i.  e.,  formed  into  fibres  of  definite  form 
as  the  result  of  some  special  plant  organism.  However,  it  must 
be  borne  in  mind  that  whatever  the  form  in  which  cellulose  occurs 
it  is  chemically  the^l^ame. 

One  of  the  purest  forms  of  cellulose  of  natural  occurrence  is 
ordinary  cotton  wool,  the  analysis  of  which  according  to  Muller, 
is : 

Cellulose .  91 .35  per  cent. 

Water .  7  -00  per  cent. 

Fatty  Substances .  o .  40  per  cent. 

Nitrogenous .  0.50  per  cent. 

Ash  (mineral) .  0.12  per  cent. 

Cuticular  matter .  0.63  per  cent. 

Cellulose  in  its  purest  form  is  a  white  substance,  the  form 
varying  according  to  the  substance  from  which  it  has  been  pre¬ 
pared.  It  is  prepared,  when  desired  pure,  by  washing  some  natu¬ 
ral  cellulose-containing  material  with  various  chemical  reagents 
which  wash  away  all  the  other  bodies  present  except  the  cellulose. 
As  could  be  inferred  from  the  above  remarks  regarding  its  method 
of  preparation,  cellulose  is  a  very  inert  substance,  hardly  being 
affected  at  all  by  chemicals.  An  ordinary  laboratory  filter  pa¬ 
per,  which  resists  most  chemical  solutions,  is  almost  pure  cellu- 

Almost  the  only  chemical  reagent  that  will  dissolve  cellulose 
is  Schweitzer’s  Reagent,  which  consists  of  copper  hydroxide  dis¬ 
solved  in  ammonia.  This  reaction  is  made  use  of  in  the  piepara- 
tion  of  artificial  silk  and  also  in  numerous  tests  for  cellulose.  _ 

Apart  from  the  role  it  plays  in  paper  technology,  cellulose  is 

5 


6  MODERN  PULP  AND  PAPER  MAKING 

important  as  being-  the  basic  material  of  gun-cotton,  many  military 
and  industrial  explosives,  celluloid,  collodion,  artificial  silk,  air¬ 
plane  dopes,  etc. 

According  to  Griffin  and  Little,^  spruce  ground  wood  contains 
about  53  per  cent  cellulose.  Reid-  reports  poplar  wood  as  yield¬ 
ing  41  per  cent  cellulose.  Griffin  and  Little^  state  that  unbleached 
sulphite  pulp  made  from  spruce  contains  80.8  per-cent  cellulose 
and  the  same  authors  mention*  experiments  in  which  poplar  wood 
yielded  by  the  sulphite  process  55.18  per  cent  cellulose. 

According  to  Muller,®  the  following  are  the  percentages 
of  cellulose  contained  in  a  number  of  European  woods: 


Poplar . 

Fir . 

Birch . 

Willow . 

Scotch  Pine 
Chestnut.  . . 

Linden . 

Beech . 

Ebony . . 


62.77  per  cent. 

56.99  per  cent. 
55 . 52  per  cent. 
55 . 72  per  cent. 
53.27  per  cent. 
52 . 64  per  cent. 
53 . 09  per  cent. 
45 . 47  per  cent. 

29 . 99  per  cent. 


The  following  table®  gives  the  composition  of  some  of  the 
more  important  Canadian  woods  : 


Age  Diam.  Soluble  in 

Material  by  annual  without  Cellulose  Liquids  boiling  water 

wings  bark  %  %  % 

Black  spruce .  74  9)^  50.64  27.59  7  24 

Red  spruce .  69  loj^  51.80  28.45  S-oS 

White  spruce .  83  10^  56.48  27.58  3.00 

White  spruce .  50  7^  56.40  27.00  4.93 

Balsam .  54  6%  50.98  32.75  4.80 

Jack  pine..., .  61  8^  49.24  30.43  6.73 

Hemlock .  120  12  47-70  . 


Of  the  materials  other  than  woods,  linen  (the  fibers  of  the 
flax  plant)  contains  from  70  to  80  per  cent  cellulose;  jute,  from 
60  to  64  per  cent  cellulose ;  various  straws  from  48  to  53  per  cent 
cellulose ;  esparto  grass  from  46  to  59  per  cent  cellulose ;  manila 
hemp  about  50  per  cent. 

Such  figures  are  the  result  of  laboratory  experiments  where 
analytical  means  were  adopted  leading  to  the  separation  and  esti¬ 
mation  of  all  the  cellulose  present.  They  do  not  necessarily  have 
any  definite  relation  to  the  amount  of  pulp  that  could  be  pro¬ 
duced  from  such  substances  under  practical  working  conditions. 


’The  Chemistry  of  Paper-Making,  pg.  120. 

"  Jl.  Soc.  Chem.  Ind.  5  (1886),  273. 

”  The  Chemistry  of  Paper  Making,  i)g.  267. 

■*  The  Chemistry  of  Paper  Making,  pg.  269. 

®  Die  Pflanzenfaser. 

“Dr.  Bjarne  Johnsen.  “Paper”  XX,  No.  8,  pg.  16  (1917). 


MATERIALS  OF  PULP 


7 

In  this  connection  the  following  table^  giving  the  yields  of 
pulp  on  a  manufacturing  scale  may  be  of  interest : 

Yields  of  Pulp  on  a  Manufacturing  Scale 


Rags . .  70-80  per  cent  paper 

Esparto .  40“45  “  “ 

Straw .  40-50  “  “ 

Wood  (by  sulphite  process) .  40-50  “  “ 

Waste  fibres,  waste  paper,  bagging,  etc. .  .  75-90  “  “ 

Bamboo .  ^o  “  “ 

Jute .  50  “  “ 


It  should  be  remembered  that  in  general  the  percentage  yield 
varies  with  the  quality  of  the  paper  being  produced  and  as  a  rule 
the  higher  the  quality  of  the  paper  the  lower  the  percentage  yield 
owing  to  the  greater  severity  of  the  processes  the  raw  material  is 
submitted  to. 

Almost  all  vegetable  structures  contain  cellulose  in  some  form 
and  to  some  extent  and  consequently  a  great  variety  of  materials 
have  been  suggested  from  time  to  time  as  raw  materials  for  paper. 
It  is  not  possible  in  this  book  to  deal  with  all  these  materials,  and 
attention  will  be  directed  only  to  those  that  are  the  basis  of  large 
actual  manufacturing  operations.  It  should  not  be  inferred,  how¬ 
ever,  that  study  and  research  concerning  new  materials  for  paper 
is  not  worthy  of  constant  attention,  as  it  indeed  is,  owing  to  the 
strain  the  modern  demand  for  paper  is  putting  on  the  ordinary 
present-day  sources  of  pulp. 

As  stated  above,  almost  any  vegetable  material  of  fibrous 
nature  can  conceivably  be  used  as  a  source  of  pulp.  The  determin¬ 
ing  factors  as  to  whether  such  a  line  of  manufacture  is  attractive 
or  not  are  the  value  of  the  product  and  the  cost  of  manu¬ 
facture.  Scientific  researches  will  indicate  whether  a  usable  pa¬ 
per  can  be  made  from  a.  given  material,  but  they  will  not  yield  an 
answer  to  the  problem  as  to  whether  it  can  be  made  profitably. 
The  locality  has  a  considerable  bearing  on  this.  There  are,  un¬ 
doubtedly,  places  where,  on  account  of  the  distance  of  sources 
of  supply  of  the  usual  raw  materials,  extraordinary  materials 
can  be  profitably  used  to  supply  the  local  demand. 

It  is  impossible  here  to  submit  a  detailed  analysis  of  the  cost 
of  making  paper  from  different  materials,  but  in  general  it  might 
be  said  that  the  cost  of  chemicals  is  greater  per  ton  of  product 
for  paper  made  from  wood  than  from  most  other  materials.  Also 
the  time  required  for  cooking  is  greater.  However,  wood  yields 
a  desirable  product — long,  strong  fibres — and  when  the  whole  cost 
of  treatment — the  subsequent  operations  as  well  as  the  cooking — 
is  taken  into  consideration  the  result  will  be  found  to  favor  the  use 
of  wood. 

A  new  paper  material  has  little  chance  of  success  in  ordinary 
localities  unless  it  will  give  an  equal  amount  of  as  good  a  quality 
of  paper  as  the  present  materials. 

^  F.  P.  Veitch:  U.  S.  Dept,  of  Agriculture,  Bur.  of  Chem.,  Cir.  41. 


8  MODERN  PULP  AND  PAPER  MAKING 

Fibres  Used  In  Paper  Making.  , 

Griffin  and  Little’^  divide  the  fibres  commonly  used  in  paper¬ 
making  into  the  following  classes : 

(1)  Seed-hairs,  of  which  cotton  is  the  only  representative. 

(2)  Bast-fibers,  such  as  linen,  jute,  manila,  etc. 

(3)  Those  derived  from  whole  cells  or  leaves,  such  as  straw  ' 
and  esparto. 

(4)  Those  derived  from  wood. 

The  first  two  classes  find  their  way  into  practical  paper  mak¬ 
ing,  chiefly  as  rags  and  jute  materials ;  the  third  class  is  used  in 
straw  boards,  papers  made  from  esparto,  etc.,  while  the  fourth  .is 
by  far  the  greatest  in  importance  in  modern  paper  making,  espe¬ 
cially  in  America,  being  the  raw  material  of  most  of  our  paper — 
newsprint,  book  papers,  bag  and  wrapping  paper,  and  all  but  the 
finest  writings. 

While  it  is  intended  to  deal  with  the  treatment  of  rags,  jute, 
straw,  esparto,  etc.,  in  an  adequate  manner  in  the  present  work, 
it  is  the  author’s  conviction  that  the  preponderance  of  emphasis 
should  be  on  the  use  of  wood  in  paper  making,  as  that  is  the  line 
of  most  importance  in  modern  — American  papermaking. 

Wood. 

Different  characteristics  are  required  of  woods  according  to 
whether  they  are  to  be  used  for  chemical  pulps  or  for  mechanical 
pulp.  There  are,  however,  many  types  of  wood  which  are  suit¬ 
able  for  both  branches  of  pulp  making,  and  this  is  especially  true 
of  spruce,  at  present  the  most  important  raw  material  of  the  pa¬ 
permaking  industry. 

In  the  manufacture  of  wood  pulps  the  chief  woods  used  are 
as  follows : 

For  the  manufacture  of  mechanical  pulp :  spruce,  hemlock, 
balsam,  fir,  aspen,  poplar  and  willow. 

For  the  manufacture  of  sulphite  pulp,  usually  the  same  woods 
as  in  the  above  list  for  mechanical  pulp. 

For  the  manufacture  of  soda,  sulphate  and  Kraft  pulps: 
spruce,  tamrack,  larch,  hemlock,  redwood,  cypress,  balsam,  jack 
pine,  southern  pine,  poplar  and  aspen. 

The  best  white  pulps  are  obtained  from  spruce.  It  is  by  far 
the  most  important  of  all  species  for  both  mechanical  and  chemical 
pulps.  From  a  chemical  standpoint  it  is  desirable  as  it  contains  a 
maximum  percentage  of  cellulose.  The  fibres  are  longer,  more 
flexible  and  stronger  than  most  other  woods.  Moreover,  abun¬ 
dant  supplies  of  spruce  are  obtainable  in  the  United  States  and 
Canada,  as  well  as'  in  other  countries,  although  well  regulated 
plans  of  forest  conservation  will  need  to  be  carried  out  if  this 
supply  is  to  be  maintained  indefinitely. 

From  a  microscopical  standpoint  the  cells  from  different  trees 
present  different  appearances,  and  those  of  the  conifers,  such  as 

^  The  Chemistry  of  Paper-Making,  pg.  330. 


MATERIALS  OF  PULP 


9 


PuLPwooD  Consumption:  Quantity  of  Wood  Consumed,  by  Kinds  and  Processes  of 

Manufacture,  1918  i 


Reduced  by — 


Kind  of  Wood 


Aggregate 

quantity 


Mechanical 

process 


Sulphite 

process 


Soda 

process 


Cords 


Cords 


Total 


5,250,794 


1,345,435 


Cords  Cords 

2,860,172  748,638 


Spruce: 


Domestic 

Imported 

Hemlock . 

Balsam  fir ... . 
Poplar: 


2,204,143 

666,164 

836,406 

368,117 


911,483 

232,914 

51,803 

80,016 


1,250,909 

426,114 

745,640 

245,904 


5,612 

5,792 

1,1.34 

7,753 


Domestic . 

Imported . 

Jack  pines . . . 

Yellow  pine . 

Yellow  poplar . 

Tamarack . 

Gum . 

White  fir . 

Cottonwood . 

Basswood . 

White  pine . 

Beech,  birch,  maple  and  chestnut 

All  other  species . 

Slabs,  and  other  mill  waste . 


210,849 

78,354 

1.52,124 

133,774 

61,247 

52,031 

47,145 

35,119 

18,685 

12,110 

10,183 

202,930 

6,810 

154,603 


19,124 

6,468 

17,487 

7,662 

665 

728 

28 

7,506 


21 

1,546 


37,072 

8,099 


3,576 


6,438 


27,613 

72 


154,6.53 

63,787 

124,090 

31,546 

60,582 


47,117 


18,613 

12,089 


1,000 


7,984 


107,735 


201,930 

6,810 

7,130 


Sulphate 

process 


Cords 

296,549 


36,139 

1,344 

37,829 

34,444 


10,547 

90,990 


,44,865 


8,637 


31,754 


1  Pulpwood  Consumption  and  Wood  Pulp  Production,  1018.  United  States  Department  of 
Agriculture,  Forest  Service,  in  co-operation  with  the  News  Print  Service  Bureau.  Bulletin 
(unnumbered)  by  Franklin  H.  Smith,  Statistician  in  Forest  Products. 


spruce,  pine,  fir,  hemlock,  balsam,  etc.,  closely  resemble  one  an¬ 
other.  By  the  use  of  a  microscope  and  careful  training  along 
that  line,  the  different  fibres  can  be  recognized  and  the  different 
types  of  wood  that  have  been  used  to  make  up  a  sheet  of  paper 
can  be  detected.  This  subject  will  be  more  fully  dealt  with  in  the 
chapter  on  the  testing  of  paper. 

Spruce:  This  is  the  most  important  wood  for  the  manufacture 
of  both  mechanical  pulp  and  chemical  pulp.  There  are  several 
species  such  as  black  spruce,  and  white  spruce  which,  from  the 
paper  maker’s  point  of  view,  may  be  considered  as  identical. 
Spruce  readily  yields  a  strong,  long  fibre  when  treated  by  the  sul¬ 
phite  process.  With  the  mechanical  process,  when  carefully 
ground  with  tolerably  dull  stones  at  a  low  temperature,  the  cor¬ 
rugations  of  the  stones  being  kept  fine  and  uniform,  spruce  yields 
the  best  class  of  ground  wood,  i.  e.,  that  which  approximates  most 
nearly  to  sulphite.  This  involves  a  high  power  consumption  (e. 
g.,  55  to  loo  H.  P.  per  ton  of  product).  In  the  manufacture  of 
market  paper,  where  long  flexible,  strong  fiber  is  desired,  spruce 
is  an  ideal  material.  Spruce  will  yield  about  1,150  lbs.  air-dry 
pulp  per  cord  of  wood  by  the  sulphite  process. 

Balsam:  This  wood  does  not  equal  spruce  as  raw  material 
for  either  the  sulphite  or  the  mechanical  process.  It  gives  a 
smaller  yield  of  pulp  per  cord  of  wood  and  produces  a  fibre  of  an 
altogether  different  character.  The  fibre  carries  more  pitchy 


10 


MODERN  PULP  AND  PAPER  MAKING 


i 

A 

■*3 

E 

o 

C 

'c?i 

ci 

> 

3 

C3 

T3 

0) 

a 

o 

1* 

K 

s 

‘3 

a 

‘«3 

:2 

g 

z 

is 

S 

(2 

O) 

:z: 

MATERIALS  OF  PULP 


II  ■ 

material.  This  causes  trouble  later  on,  and  is  a  detriment  when 
the  pulp  is  to  be  bleached.  Although  the  balsam  fibres  are  of  a 
length  about  equal  to  the  spruce  fibres,  they  are  much  softer  and 
more  flexible,  and  when  made  up  into  a  sheet  of  paper  it  is  very 
easy  to  tell  the  difference.  Balsam  when  pulped  by  the  sulphite 
process  will  yield  about  950  lbs.  air-dry  pulp  per  cord  of  wood. 

Balsam  pulp,  mixed  with  a  small  percentage  of  spruce  sulphite, 
is  very  satisfactory  for  some  bag  papers.  Such  papers  have  good 
tearing  and  cleavage  quality,  a  soft  silky  feel,  and  are  very  flexi¬ 
ble.  The  above  results  can  only  be  achieved,  however,  when  the 
stock  has  been  made  with  great  care. 

Hemlock:  The  general  character  of  hemlock  sulphite  pulp 
is  similar  to  spruce,  but  of  somewhat  inferior  quality.  Hemlock 
ground  wood  has  a  decided  reddish  tinge,  which  is  an  undesirable 
feature.  The  fibres  from  hemlock  are  shorter  than  spruce,  but 
probably  sufficiently  long  for  the  cheaper  sorts  of  paper. 

J.  H.  Thickens  ^  says :  “One  who  is  accustomed  to  handling 
spruce  ground  wood  will  not  be  favorably  impressed  with  the  ap¬ 
pearance  of  either  hemlock  or  jack  pine  pulp.  This  is  particu¬ 
larly  true  of  the  hemlock  sheet.  Both  pulps  are  somewhat  softer 
in  texture  than  spruce,  and,  altogether,  are  not  of  so  pleasing  an 
appearance  as  the  present  commercial  product.” 

Hemlock  sulphite  is  highly  adaptable  to  making  high  water 
finish  papers.  It  has  the  property  of  taking  on  a  high  water  finish 
more  readily  than  any  other  kind  of  sulphite  stock.  Hemlock 
will  yield  by  the  sulphite  process  about  800  lbs.  air-dry  pulp  per 
cord  of  wood. 

Poplar  and  Aspen:  These  woods  are  very  largely  used  in 
making  soda  pulp,  although  poplar  is  quite  extensively  used  for 
sulphite  pulp  also.  It  has  been  found  that  under  careful  treat¬ 
ment  these  woods  give  a  highly  characteristic  soda  pulp  that  is 
soft,  silky  and  pliable  and  well  adapted  to  book  and  other  such 

papers.  _ 

According  to  H.  K.  Surface  ^  of  the  U.  S.  Forest  Service, 
“Soda  poplar  pulp  is  the  best  known  substitute  for  esparto  pulp. 
Its  principal  use  is  in  the  bleached  form,  in  conjunction  with  other 
pulps,  and  it  enters  into  the  highest  grade  of  papers  for  which  it 
is  especially  adapted.  Such  papers  are  book,  magazine,  antique, 
coated,  lithograph,  map,  envelope,  writing,  wood  blotting,  and 
the  soft  bulky  papers  sometimes  required  for  special  purposes. 
The  pulps  usually  mixed  with  the  soda  pulps  in  making  these  pa¬ 
pers  are  the  longer-fibred  pulps,  such  as  rag  pulps  and  sulphite 
wood  pulps ;  and  the  proportion  in  which  they  enter  the  product 
varies  from  o  to  80  per  cent,  depending  upon  the  quality  of  the 
product  and  the  uses  to  which  it  is  to  be  put.” 

Poplar  soda  pulp  lacks  strength,  and  consequently  it  will  gen¬ 
erally  be  found  with  some  other  pulp  which  adds  the  necessary 

1  Experiments  with  jack  pine  and  hemlock  for  mechanical  pulp.  U.  S.  Department 
of  Agriculture.  Forest  Service,  1912. 

*  Paper:  xxiii  (1919),  23,  pg.  5°. 


‘  12  MODERN  PULP  AND  PAPER  MAKING 

long,  strong  fibre  to  give  strength  and  endurance.  Poplar  soda 
pulp  is  also  desirable  becaues  of  its  opacity,  a  sheet  made  up 
largely  from  this  pulp  being  more  bulky  and  opaque  than  one 
composed  more  of  sulphite  or  rag  pulp. 

Some  poplar,  aspen  and  similar  woods  are  worked  up  by  a 
modification  of  the  sulphate  process  to  form  what  is  known  as 
“American  aspen  cellulose,”  or  sometimes  as  “poplar  soda  pulp.” 
The  fibers  are  shorter  than  in  spruce  sulphite,  but  the  pulp 
bleaches  easily  and  it  is  extensively  used  in  European  papers  as  a 
substitute  for  rag  pulp. 

Yellow  Pine:  Considerable  work  has  been  done,  resulting  in 
at  least  some  cases  in  commercial  operations,  on  the  use  of  yellow 
pine  chips  in  the  Kraft  process.  ‘  The  pitch  present  in  this  wood 
prevents  its  use  for  the  manufacture  of  sulphite  pulp.  During 
the  cooking  operation  in  the  Kraft  process,  however,  the  resins 
and  pitch  present  in  the  wood  are  saponified  and  thus  rendered 
soluble  so  they  can  be  washed  out.  The  fibers  are  characterized 
by  unusual  strength.  Some  work  has  been  done  in  the  South  on 
extracting  the  resins  and  pitch  with  solvents  and  then  using  the 
extracted  chips  as  raw  material  for  pulp.  Planer  shavings  have 
been  utilized  in  this  manner  with  some  success. 

The  series  of  tables  on  page  13  and  succeeding  pages,  which 
record  experiments  carried  out  by  the  U.  S.  Forest  Service  in  a 
miniature  pulp  mill,  afford  valuable  data  as  to  the  pulp  making 
properties  of  a  large  number  of  American  woods. 

Straw  and  Esparto. 

Straw  is  converted  into  a  bleached  pulp  for  use  in  newsprint 
and  magazine  papers,  and  is  also  extensively  worked  up  into  pulp 
for  strawboard.  The  treatment  differs,  depending  on  whether 
bleached  pulp  for  paper  manufacture  or  strawboard  pulp  is  to  be 
made. 

The  following  description  of  the  process  whereby  the  various 
kinds  of  straw  are  converted  into  bleached  straw  pulp  will  also 
apply  in  general  to  esparto. 

In  America  esparto  is  of  less  importance  than  in  Great  Britain 
and  on  the  continent  of  Europe,  where  it  is  a  very  important  raw 
material.  It  is  a  grass  which  grows  wild  in  Spain  and  the  North 
of  Africa.  Spanish  esparto  is  the  better  grade.  The  fibers  are 
shorter  than  straw  fibers,  but  tougher.  The  following  analyses 
of  esparto  are  those  made  by  Muller : 


Spanish 

African 

Cellulose . 

.  48.25  , 

45.80 

Fat  and  wax . 

2.62 

Aqueous  extract . 

.  10.19 

9.81 

Pectous  substances . 

.  26,39 

29  30 

Water . 

.  9.38 

8.80 

Ash . 

.  3-72 

3  67 

MATERIALS  OF  PULP 

Recobd  of  Experimental  Cooks  Using  the  Sulphite  Process 


13 


Species 


Bald  cypress . 
Cotton  gum . 


Ship¬ 

ment 

number 


Cook 

num¬ 

ber 


Douglas  fir.  .  .  . 
Engelmann  spruce 


Grand  fir . 


S-3 

S-2 

S-498 

S-502 


S-39 


Hemlcok . 

S-8 

Incense  cedar .... 

S-36 

Jack  pine . 

L-26B 

Loblolly  pine . 

S-5 

S-33 

Lodgepole  pine  . . . 

S-499 

Red  spruce . 

Scrub  pine . 
Tamarack . 


Western  hemlock 


White  fir. 


S-11 

S-19,21 

L-26E 

S-38 

S-35 

S-35,37 


1 

2 

3 

1 

2 

3 

4 
1 
2 
1 
2 

3 

4 
6 
6 

12 

1 


Chip 

charge, 

bone- 

dry 

weight 


Cooking  liquor  charge  at  start  of  cook 


Water 
in  chips 


Concentrations 


Pounds 


2 

3 

4 

5 
1 
2 
1 
2 
3 

6 

7 

8 
9 
1 
3 
1 
2 
3 
1 
2 
3 
6 

7 

8 
9 
2 

3 

4 

5 
1 
2 
3 

14 

15 

16 
17 

1 

2 

3 

4 

5 
1 
2 
1 

4 

5 
8 


Per  cent 


36.7 

40.5 

29.6 

34.8 

39.8 

22.3 

22.7 
16.0 
17.0 

13.9 
14.0 

13.7 

12.7 

10.9 

18.7 
17.0 

14.6 

15.4 

16.9 

18.8 

21.3 

36.4 

36.1 

14.4 

15.5 

16.7 

13.9 

14.6 

13.7 

14.8 
29.5 
42.0 

15.8 

19.2 
19.2 

15.1 

15.2 

15.8 

17.3 

17.1 

19.4 

20.2 
30.0 

28.9 

29.2 

17.2 

30.3 
35.0 

37.3 
23.2 
23.2 
23.2 

23.2 

15.4 
19.0 

18.3 

45.3 

46.7 
16.0 
16.1 
12.6 

25.4 

26.8 
48.9 


Total 
SO  2 


Grams 
per  liter 


9.1 

11.1 

18.2 

14.9 

13.1 

12.2 
10.2 

56.4 

47.2 

79.9 

78.1 
118.4 

96.3 
128.8 

33 . 6 

47.1 
71.8 

62.6 

47.7 

33.3 

17.5 
9.9 

10.8 

38.9 

28.9 

19.5 

80.4 
70.8 
82.0 

78.6 

18.6 

13.1 

58.2 

30.2 

30.2 
66.1 

64.7 

57.8 

44.3 

45.9 

28.7 

23.8 

16.7 
21.1 

19.8 

16.3 

15.5 

14.3 

11.9 

7.6 

7.7 
7.7 
7.7 

29.9 
58.0 

36.5 

32.5 

28.5 

24.7 

24.1 

58.8 

57.3 

49.1 
22.7 


Com¬ 
bined 
SO  2 


Grams 
per  liter 


43.8 

43.4 

42 . 6 

42.2 

43.1 

42.8 
42.8 
41.0 

38.5 

41.5 

41.3 

41.5 

41.2 

40.7 
40.0 

39.5 
41.0 
41.0 

41.5 

40.5 

36.1 

43.3 

42.5 

35.5 
40.0 

38.7 
41.0 
40.0 
40.0 

45.3 
41.0 

43.8 

43.2 

42.2 

42.6 
41.0 

39.8 

40.6 

39.5 
40.0 

40.7 

34.7 
40.0 

42.2 

42.9 

38.5 

43.3 

42.5 

43.5 
49.0 
50.0 
49.0 
51.0 

36.9 

38.7 
40.0 

40.7 
38.0 
37.0 
40.0 
43.0 

36.3 

41.1 

40.1 


Free 
SO  2 


Grams 
per  liter 


15.4 

15.0 

14.3 

14.1 

14.7 

14.2 

14.3 

10.3 

10.4 

10.8 
10.8 
10.8 

10.5 
11.0 

10.3 

11.7 
11.0 
12.2 

10.8 
10.8 

12.7 

14.8 

13.4 
9.0 

9.6 

9.7 

11.5 
11.5 
11.0 
15.0 
11.5 

15.2 

14.3 

13.9 

14.2 
9.6 
9.6 

12.9 

10.7 

14.1 

11.5 

12.8 

12.3 
11.7 

15.9 
10.0 

15.2 

15.2 

15.1 

18.5 
19.0 
19.0 

19.5 
9.6 

9.2 
9.6 

11.3 

10.2 

8.5 

9.6 
10.0 

8.3 

8.7 
9.6 


Com¬ 

bined 

MgO 


Grams 
per  liter 


Grams 
per  liter 


28.4 

28.4 

28.3 
28.1 

28.4 
28.6 

28.5 
30.7 
28.1 
30.7 

30.5 
30.7 

30.7 

29.7 

29.5 

27.8 
30.0 

28.8 

30.7 

29.7 

23.4 

28.5 

29.1 

26.5 

30.4 
29.0 

29.5 

28.5 
29.0 

30.3 

29.5 

28.6 

28.9 

28.3 

28.4 

31.4 

30.2 

27.7 

28.8 

25.9 

29.2 

22.4 

27.9 

30.5 
27.0 

28.5 
28.1 

27.3 

28.4 

30.5 
31.0 
30.0 

31.5 

27.3 

29.5 

30.4 

29.4 
27.8 

28.5 

30.4 
33.0 
28.0 

32.4 

30.5 


2.7 

2.7 

2.8 
2.8 
2.8 
2.7 
2.9 

2.7 
3.0 
2.9 

3.2 

2.8 
2.8 

3.3 


2.3 

2.5 

2.5 
3.7 

3.7 

3.5 

4.8 


2.5 

2.5 

3.3 

2.8 

3.7 

3.0 

3.2 


.1 


Com¬ 

bined 

CaO 


5.9 
6.1 
6 
6 
1.0 

2.4 

2.5 

2.9 

2.6 
2.2 

2.5 

2.6 
2.2 
2.3 
2.5 


5.3 

5.4 
5.6 
5.6 

5.6 

5.4 

5.7 

5.3 
6.0 
5.7 

6.3 
5.6 
5.6 

6.5 


4.6 
4.9 
5.0 
5.0 
5.0 

4.7 
6.5 


4.9 

4.9 
6.6 
5.5 

7.3 

5.9 

6.3 


8.0 

8.2 

8.2 

8.4 

7.0 

4.7 
4.9 

5.8 

5.3 

4.4 

4.9 
5.1 
4.3 

4.5 
4.9 


14 


MODERN  PULP  AND  PAPER  MAKING 

Record  of  Experimental  Cooks  Using  the  Sulphite^  Process — Continued 


Cooking  liquor  charge  at  start  of  cook 


Species 

Ship¬ 

ment 

number 

Cook 

num¬ 

ber 

Quantity  per  pound  of  chips,  bone-dry  weight 

]  Total 
liquor 

Total  S. 

Com¬ 
bined  S. 

Free  S. 

Com¬ 

bined 

MgO 

Com¬ 

bined 

CaO 

Gallons 

Per  cent 

Per  cent 

Per  cent 

Per  cent 

Per  cent 

Bald  cypress . 

S-3 

1 

1.09 

19.9 

7.0 

12.9 

2 

.99 

17.9 

6  2 

11.7 

3 

1.52 

27.1 

9.1 

18.0 

Cotton  gum . 

S-2 

1 

1.15 

20.2 

6.7 

13.5 

2 

1.01 

18.2 

6.2 

12.0 

3 

2.02 

36.1 

12.0 

24.1 

4 

1.98 

35.4 

11.8 

23.6 

Douglas  fir . 

S-498 

1 

2.82 

48.2 

12.1 

36.1 

6.3 

12.5 

2 

2.65 

42.6 

11.5 

31.1 

6.0 

11.8 

Engelmann  spruce. 

S-502 

1 

3.24 

56.1 

14.6 

41.5 

7.6 

15.0 

2 

3.20 

55.2 

14.4 

40.8 

7.5 

14.9 

3 

3.28 

56.7 

14.7 

42.0 

7.7 

15.2 

4 

3.53 

60.7 

15.5 

45.2 

8.1 

15.9 

5 

4.11 

69.9 

18.9 

51.0 

9.8 

19.5 

6 

2.41 

40.2 

10.6 

29.6 

5.4 

10.6 

12 

2.65 

43.6 

12.9 

30.7 

6.8 

13.3 

Grand  fir . 

S-39 

1 

3.09 

52.9 

14.2 

38.7 

7.4 

14.6 

2 

2.92 

50.1 

14.9 

35.2 

7.8 

15.4 

3 

2.66 

46.0 

12.0 

34.0 

6.2 

12.3 

4 

2.40 

40.5 

10.8 

29.7 

5.6 

11.1 

5 

2.11 

31.9 

11.2 

20.7 

5.8 

11.6 

Hemlock . . 

S-8 

1 

1.10 

19.9 

6.8 

13.1 

2 

1.24 

22.1 

7.0 

15.1 

Incense  cedar . 

S-36 

1 

3.13 

47.3 

12.0 

35.3 

6.1 

12.1 

2 

2.90 

48.4 

11.6 

36.8 

6.0 

12.0 

Jack  pine . 

L-26B 

6 

2.89 

49.3 

13.9 

35.5 

8.9 

11.9 

7 

2.73 

45.7 

13.1 

32.6 

8.4 

11.3 

8 

2.91 

48.7 

13.4 

35.3 

8.6 

11.6 

9 

2.70 

51.2 

16.9 

34.2 

10.8 

14.6 

Loblolly  pine . 

S-5 

1 

1.35 

23.1 

6.5 

16.6 

3 

.95 

17.4 

6.0 

11.4 

S-33 

1 

2.85 

51.4 

17.1 

34.2 

2 

2.34 

41.3 

13.6 

27.7 

3 

2.34 

41.7 

13.9 

27.8 

Lodgepole  pine .... 

S-499 

1 

2.99 

51.2 

12.0 

39.2 

6.2 

12.3 

2 

2.96 

49.2 

11.9 

37.3 

6.2 

12.2 

3 

2.84 

48.1 

15.3 

32.8 

7.9 

15.8 

6 

2.60 

42.8 

11.6 

31.2 

6.0 

12.0 

7 

2.63 

43.9 

15.5 

28.4 

8.0 

15.9 

8 

2.32 

39.4 

11.1 

28.3 

5.8 

11.5 

9 

2.23 

32.2 

11.4 

20.8 

5.9 

11.8 

Red  spruce . 

S-11 

2 

1.33 

22.5 

7.0 

15.5 

3 

1.38 

24.4 

6.7 

17.7 

4 

1.37 

24.5 

9.1 

15.5 

5 

2.62 

42.2 

11.0 

31.2 

Scrub  pine . 

S-19,  21 

1 

1.32 

23.9 

8.4 

15.5 

2 

1.14 

20.2 

7.2 

13.0 

3 

1.21 

22.0 

7.6 

14.4 

Tamarack . 

L-26E 

14 

1,72 

35.2 

13.3 

21.9 

8.5 

11  .4 

15 

1.72 

35.9 

13.6 

22.3 

8.7 

11.7 

16 

1,72 

35.2 

13.6 

21.5 

8.7 

11  .7 

17 

1.72 

36.6 

14.0 

22.6 

8.9 

12.1 

Western  hemlock . . 

S-38 

1 

2.92 

45.0 

11.7 

33.3 

2.4 

17.  1 

2 

2.11 

34.0 

8.0 

26.0 

4.2 

8.3 

3 

2.45 

41.0 

9.8 

31.2 

5.1 

10.2 

4 

.66 

11.2 

3.1 

8.1 

1.6 

3.2 

5 

.94 

14.9 

4.0 

10.9 

2.1 

4.1 

White  fir . 

S-35 

1 

2.81 

43.3 

9.9 

33.4 

5.2 

10.2 

2 

2.79 

46.6 

11.2 

35.4 

5.8 

11.5 

S-35,  37 

1 

2.78 

49.8 

11.6 

38.2 

6.1 

11.9 

4 

1.77 

26.8 

6.2 

20.6 

3.2 

6.3 

5 

1.68 

28.7 

6.1 

22.6 

3.2 

6  3 

8 

.61 

10.2 

2.4 

7.8 

1.3 

2.5 

MATERIALS  OF  PULP 


15 


Record  of  Experimental.  Cooks  Using  the  Sulphite  Process — Continued 


Species 


Bald  cypress . 
Cotton  gum . 


Douglas  fir . 


Grand  fir. 


Hemlock.  .  . 
Incense  cedar .  .  . 


Jack  pine . 


Loblolly  pine.  .  .  . 


Lodgepole  pine  . . . 


Red  spruce . 


Scrub  pine . 


Tamarack . 


Western  hemlock 


White  fir. 


Ship-  ( 
ment  j 
number 

Dock 

lum¬ 

ber 

A 

Total  g 

S-3 

1 

Hours 

8.0 

2 

10.0 

3 

11.0 

S-2 

1 

8.0 

2 

7.5 

3 

9.0 

4 

9.0 

S-498 

1 

8.0 

2 

9.0 

»  S-502 

1 

10.0 

2 

10.0 

3 

9.0 

4 

10.0 

5 

10.0 

6 

10.0 

12 

10.0 

.  S-39 

1 

8.0 

2 

9.0 

3 

9.0 

4 

9.0 

5 

8.0 

S-8 

1 

8.5 

2 

9.0 

S-36 

1 

8.0 

2 

9.8 

3 

12.5 

L-26B 

6 

10.0 

7 

10.0 

8 

15.0 

9 

15.0 

S-5 

1 

10.0 

3 

8.0 

S-33 

1 

10.0 

2 

10.0 

3 

11.0 

S-499 

1 

8.0 

2 

9.0 

3 

12.0 

6 

10.0 

7 

9.0 

8 

11.0 

9 

12.5 

.  S-11 

2 

10.0 

3 

10.0 

4 

8.5 

5 

8.0 

. .  S-19,21 

1 

7.7 

2 

9.0 

3 

9.7 

.  L-26E 

14 

10.0 

15 

16.0 

16 

16.0 

17 

20.0 

k .  S-38 

1 

8.0 

2 

10.0 

3 

9.0 

4 

9.0 

5 

9.0 

. .  S-35 

1 

9.0 

2 

8.8 

S-35,37 

1 

8.0 

4 

8.8 

5 

8.8 

8 

9.0 

Duration  of  cooking 


I 


At  max¬ 
imum 
gauge 
pres¬ 
sure 


Hours 

0.0 

.0 

.0 

.0 

.0 

.0 

.0 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.0 

.0 

.3 

.3 

.3 

.8 

.2 

.2 

.2 

.0 

,0 

.0 

.0 

.0 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.0 

.0 

.0 

.0 

.0 

.0 

.0 

.2 

1.0 

1.3 

.8 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 

.3 


Below 

zero 

steam 

pres¬ 

sure 


Hours 

4.0 

3.8 
6.0 
3.0 

2.5 

5.5 
4.0 

4.5 

5.5 
.4.3 

4.0 

4.5 
4.3 

5.5 

4.5 

5.8 
4.0 
3.0 
4.0 
5.0 
4.0 
4.0 
4.0 
4.0 

3.8 
4.5 
6.2 

5.8 
12.2 

8.8 
2.0 
3.0 

4.5 

5.5 
6.0 

3.8 

3.5 

5.8 

5.3 

4.5 

6.3 

8.8 
7.0 
7.0 
4.0 
4.0 
3.0 
3.0 

4.5 

5.5 
9.0 

9.5 
12.5 

4.0 

5.0 

4.0 

3.0 

4.0 

5.3 
4.0 

3.3 

5.5 
4.7 

4.5 


At  max¬ 
imum 
steam 
pres¬ 
sure 


Hours 

2.0 
2.0 
3.0 
2.0 
1.2 
3.5 
3.0 
3.0 
3.3 
3.0 
3.0 
3.0 
3.0 
2.8 
3.3 
3.3 
3.0 

3.5 
3.0 
3.0 
3.0 

1.7 
3.0 

2.8 
3.0 
3.0 
3.0 
3.0 
3.0 
3  0 
2.7 
2.0 
2.0 
3.0 
2.7 
2.0 
3.0 
3.0 
3.0 

2.5 
3.0 

3.3 

2.5 
3.0 
3.0 
3.0 
3.0 
1.0 

2.3 

4.5 
5.0 
5.0 
5.0 

1.5 
3.0 
3.0 
3.0 
3.0 
1.8 

2.6 

2.5 

2.3 

2.8 

3.3 


Hours 

2.7 

3.8 

4.7 
3.0 

1.8 
4.0 
4.0 
2.0 
3.0 
3.0 
3.0 
3.0 
3.0 
4.0 
2.8 
4.0 
2.0 
2.0 
2.0 
3.0 
2.0 
3.0 
2.0 
2.0 

2.5 
4.0 
3.2 

3.2 

4.8 
5.0 

.1 
2.0 

4.3 
4.0 

5.3 
2.0 
2.0 
3.0 
3.0 

2.8 

3.0 

1.5 
.1 
.1 

2.0 
2.0 

2.5 
3.0 

3.5 
3.0 
4.0 
5.0 
9.0 
2.0 
2.0 
2.0 
2.0 
2.0 
4.0 
2.8 

1.5 
4.0 
3.0 
2.0 


Maximum 

pressures 


Gauge 

Steam 

Lbs.  per 

Lbs.  per 

sq.  in. 

sq.  in. 

85 

58 

88 

60 

90 

60 

85 

60 

84 

58 

80 

56 

86 

56 

80 

60 

80 

60 

90 

70 

90 

70 

80 

60 

90 

70 

80 

60 

90 

70 

80 

60 

80 

60 

80 

60 

80 

60 

80 

60 

80 

60 

86 

59 

85 

60 

80 

60 

.  88 

64 

90 

68 

80 

40 

80 

46 

73 

46 

75 

46 

80 

•  60 

85 

60 

85 

60 

85 

60 

85 

60 

80 

60 

90 

70 

80 

60 

90 

70 

80 

60 

90 

62 

90 

60 

70-80 

50 

70-80 

60 

85 

60 

80 

60 

84 

60 

85 

59 

90 

60 

80 

46 

80 

46 

80 

46 

80 

38 

80 

60 

80 

60 

80 

60 

80 

60 

80 

60 

80 

60 

80 

62 

80 

60 

80 

60 

80 

54-68 

so 

60 

i6 


MODERN  PULP  AND  PAPER  MAKING 

Record  of  Experimental  Cooks  Using  the  Sulphite  Process — Continued 


Species 

Ship¬ 

ment 

number 

Cook 

num¬ 

ber 

Yields 

Quality  of  pulps 

Screenet 

pulp 

1  Screen¬ 
ings 

Ash 

Cellulose 

Bleach 

tequiree 

Loss  on 
bleach- 
1  ing 

Per  cent 

Per  cent 

Per  cent 

Per  cent 

Per  cent 

Per  cent 

Bald  cypress . 

S-3 

1 

43.5 

13.9 

1,18 

72.0 

2 

46.9 

12.4 

^68 

75.6 

126.0 

12.9 

3 

1.5 

.52 

81.5 

52.0 

3.8 

Cotton  gum . 

S-2 

1 

43.0 

11.8 

.99 

83.5 

35.0 

4.6 

2 

42.6 

1.3 

■  .78 

83.6 

17.0 

2.1 

3 

44.5 

1.9 

1.13 

81.5 

20.5 

3.3 

4 

43.5 

1.4 

.99 

82.7 

35.0 

5.2 

Douglas  fir . 

S-498 

1 

38.8 

16  0 

1 .25 

70  0 

11  9 

2 

32.9 

25.8 

Engelmaiin  spruce . 

S-502 

1 

34.7 

1.9 

.89 

86.7 

15.0 

2.9 

2 

39.0 

.3 

.75 

87.2 

13.5 

2.5 

3 

45.2 

1.2 

.89 

85.7 

22.5 

5.1 

4 

45.7 

•  .5 

1.12 

87.7 

12.0 

2.4 

5 

52.5 

.5 

.98 

88.0 

12.3 

2.2 

6 

40.0 

.3 

.86 

85.9 

12.5 

2.3 

12 

40.1 

.5 

1.35 

85 . 6 

21.0 

5.1 

Grand  fir . 

8-39 

1 

51.4 

1  7 

1  71 

80  0 

12  8 

2 

24.1 

19.4 

2.00 

72.8 

3 

46.0 

.6 

.76 

26.6 

1.6 

4 

46.9 

1.5 

.86 

28.0 

5.7 

5 

46.4 

2.4 

2.78 

40.0 

7.8 

Hemlock . 

S-8 

1 

43.8 

11.5 

.75 

81.2 

85.0 

10.0 

2 

39.2 

13.7 

.38 

85.8 

37.0 

4.9 

Incense  cedar . 

S-36 

1 

40.8 

8.3 

2.37 

71.3 

2 

37.9 

1  .3 

1.38 

78.6 

3 

16.3 

.4 

1.35 

80.8 

Jack  pine . 

L-26B 

6 

45.5 

4.9 

7 

34.8 

17.2 

8 

40.7 

5.9 

9 

53.2 

3.0 

Loblolly  pine . 

S-5 

1 

1  3 

83 

85  4 

35  0 

7  7 

3 

12.1 

.57 

83.1 

39.0 

5.7 

S-33 

1 

4.50 

2 

1  06 

76  6 

72  0 

9  3 

3 

1.45 

80.0 

12  9 

Lodgepole  pine .... 

S-499 

1 

43.  a 

7.6 

1.15 

80.3 

50.0 

8.8 

2 

43.1' 

2.4 

1.29 

81.6 

39.0 

7.0 

3 

39.9 

3.1 

2.53 

81.2 

29.0 

6.6 

0 

36.8 

.5 

.60 

78.5 

22.8 

3.8 

7 

50.9 

5.3 

6.84 

75.5 

43.0 

13.7 

8 

32.4 

5.7 

.65 

23.0 

3.6 

9 

33.5 

.3 

.44 

16.8 

2.5 

Red  spruce . 

S-11 

2 

3 

18.2 

1.96 

73.5 

98.0 

22.0 

4 

1.7 

.67 

86.1 

17.0 

3.6 

5 

53.9 

1.7 

2.00 

84.4 

35.0 

6.3 

Scrub  pine . 

S-19,  21 

1 

16  7 

1.13 

65  0 

9  5 

2 

13.1 

.59 

67.0 

7.0 

3 

11.1 

.43 

20.4 

4.1 

Tamarack . 

I^26E 

14 

42.8 

8.4 

15 

46.0 

.8 

16 

45.8 

1.5 

17 

46.7 

1.7 

Western  hemlock . . 

S-38 

1 

43.6 

.8 

2.41 

85.1 

44.8 

7.7 

2 

45.2 

2.5 

1.29 

83.1 

41.0 

7.6 

3 

47.3 

1.1 

1.13 

84.7 

35.0 

6.4 

4 

28.6 

18.1 

1.24 

80.3 

72.0 

11.7 

5 

42.0 

.3 

.66 

85.9 

25.0 

4.5 

White  fir . 

S-35 

1 

40.6 

1.3 

1.03 

85.8 

20.5 

4.0 

2 

42.7 

.9 

1.22 

85.1 

23.5 

4.7 

3-35,  37 

1 

45.5 

.2 

1.23 

85.6 

28.0 

4.9 

4 

48.3 

.8 

.66 

88.0 

19.0 

1.8 

5 

44.8 

.4 

.90 

83.8 

17.0 

3.2 

8 

41.4 

.7 

.43 

86.0 

12.8 

1.1 

*  Air-dry  screenings.  Percentage  based  on  bone-dry  weight  of  chips. 


-MATERIALS  OF  PULP 

Record  op  Experimental  Cooks  Using  the  Soda  Process 


17 


Species 


Aspen . 

Beech . 

Cotton  gum . 

Douglas  fir . 

Engelmann  spiuce'. 

Grand  fir . 

Incense  cedar . 

Jack  pine . 

Loblolly  pine . 

Lodgepole  pine .... 

Longleaf  pine . 

Red  alder . 

Red  maple . 

Sycamore . 

Tamarack . 

Tulip  tree . 

Western  hemlock . . 
White  fir. . 


Chip 

charge, 

bone-dry 

weight 

Cooking  liquors  at  start  of  cook 

Ship¬ 

ment 

number 

Cook 

num¬ 

ber 

Water  in 
chips 

Concentrations 

NaOH 

Na2CO.i 

Total 

Na20 

ticity 

L-19 

2 

Pounds 

39.4 

Per  cent 

9.1 

Grams 
per  liter 

80.5 

Grams 
per  liter 

2.2 

Grams 
per  liter 

63.7 

Per  cent 

97.9 

4 

40.3 

8.2 

80,2 

3.1 

64.0 

97.1 

7 

39.9 

9.8 

71.6 

2.7 

57.1 

97.2 

25 

.39.0 

8.2 

70.0 

2,1 

55 . 5 

97.8 

S-7 

5 

21.8. 

14.6 

91.0 

5.2 

73.5 

95.9 

6 

22.1 

13.0 

90.0 

6.4 

73.5 

94.9 

7 

22.1 

13.3 

90.0 

4.6 

72.5 

96.2 

8 

21.9 

14.2 

100.0 

5.8 

80.9 

95.8 

S-4 

3 

22.4 

11.8 

90.0 

5.1 

72.7 

95.9 

4 

22.1 

13.0 

90.0 

8.1 

74.5 

93.6 

S-498 

1 

40.4 

9.1 

90.0 

2.7 

71.4 

97.8 

2 

40.4 

9.1 

90.0 

2.4 

71.2 

98,0 

S-502 

4 

21.4 

16.9 

90.0 

5.0 

72.7 

96.0 

5 

21.3 

17.2 

90,0 

3.0 

71.5 

97.5 

6 

21.1 

18.6 

80,0 

2.7 

63.6 

97.5 

7 

21.2 

17.7 

90,0 

3.4 

71.8 

97.2 

8 

22.1 

13.4 

80.0 

3.2 

63.8 

97.1 

S-39 

5 

21 .9 

14.3 

90.0 

7.6 

74.2 

94.0 

6 

21.8 

14.9 

90.0 

3.4 

71.7 

97.2 

7 

21.9 

13.9 

90.0 

6.1 

73.3 

95.1 

8 

22.1 

13.2 

90.0 

4.2 

72.2 

96.6 

13 

21.4 

17.1 

80.0 

5.7 

65.3 

94.9 

15 

22.7 

14.7 

90.0 

6.7 

73,6 

94.7 

S-36 

3 

21.9 

14.4 

80.0 

3.7 

64.2 

96.6 

4 

21.6 

15.6 

80.0 

4.4 

64.6 

96.0 

5 

21.8 

14.7 

80,0 

3.7 

64.2 

96.5 

6 

22.0 

13.6 

80.0 

3.8 

64.2 

96.5 

7 

22.0 

13.9 

90.0 

3.9 

72,6 

96.0 

L-105 

1 

35.8 

39.8 

90.0 

2.4 

71.2 

98.0 

2 

35.8 

39.7 

90.0 

2.4 

71.2 

98.0 

L-2 

1 

41.0 

22.1 

90.0 

2.7 

71.4 

97.8 

S-469 

1 

22,2 

12.6 

90.0 

3.4 

71.7 

97.2 

2 

22.4 

11.7 

90.0 

3.2 

71.7 

97.4 

S-499 

4 

21.8 

14.7 

90.0 

4.9 

72.6 

96.0 

5 

21.8 

15.0 

90.0 

.4.9 

72.6 

96.0 

7 

22.2 

12.9 

80.0 

3.2 

63.9 

97.1 

8 

21.9 

14.4 

80,0 

2.8 

63.6 

97.4 

L-3 

1 

41.9 

14.6 

90.0 

2.7 

71.3 

97.8 

2 

41.9 

14,6 

90,0 

2.4 

71.2 

98.0 

3 

41.9 

14.6 

90.0 

*  2.4 

71.1 

98.0 

S-524 

4 

21.8 

14.7 

80.0 

4.4 

64.5 

96.0 

5 

21.5 

16.4 

80.0 

3.9 

64.3 

96.5 

8 

22.0 

13.8 

80.0 

2.1 

63.2 

98.0 

9 

21.5 

16.3 

80.0 

4.0 

64.3 

96.4 

10 

21.4 

16.8 

80.0 

4.0 

64.3 

96.4 

11 

21.5 

16.1 

80.0 

3.7 

64.2 

96.6 

S-14 

2 

22.3 

12.1 

80.0 

4.4 

64.4 

96.0 

3 

22.2 

12.9 

80.0 

5.9 

65.5 

94.7 

4 

22.2 

12.9 

80.0 

8.1 

66.8 

92.8 

S-18 

1 

22.0 

13.6 

80.0 

4.2 

64.4 

96,2 

2 

22.1 

.  13.2 

80.0 

4.6 

64.7 

yb . 

L-26E 

18 

40.8 

10.4 

90.0 

2.7 

71.4 

97,8 

19 

40.8 

10.4 

90.0 

2.4 

71.2 

98.0 

S-16 

4 

21.7 

15.5 

80.0 

4.6 

64.7 

95.8 

5 

21.7 

15.2 

80.0 

5.7 

66 . 3 

94.9 

6 

22.0 

13.7 

89.1 

5.4 

72.2 

95.6 

S-38 

8 

17.6 

13.8 

80.0 

4.7 

64.7 

95.9 

9 

20.1 

14.4 

80.0 

7.4 

66.3 

93.6 

S-35 

4 

11.8 

9.3 

•  87.2 

2.3 

69.0 

98.0 

i8  MODERN  PULP  AND  PAPER  MAKING 

Record  of  Experimental  Cooks  Using  the  Soda  Process— Continued 


Species 


Aspen . 


Beech . 


Cotton  gum . 
Douglas  fir.  . 


Grand  fir . 


Incense  cedar. 


Jack  pine . 


Cooking  liquors  at  start  of  cook  Duration  of  cooking 


Loblolly  pine .  . 
Lodgepole  pine . 


Longleaf  pine . , 
Red  alder . 


Red  maple. 


Sycamore . 
Tamarack . 
Tulip  tree . 


White  fir. 


Ship-  ' 
ment 
number 

Z!ook 

lum¬ 

ber 

Quantity  per  pound  of  chips, 
bone-dry  weight 

Total 

A.t  zero 
gauge 
pres¬ 
sures 

At  max¬ 
imum 
gauge 
pres¬ 
sure 

Total 

liquor 

NaOH 

NaiCOs 

Total 

NaiO 

Gallons 

Per  cent 

Per  cent 

°er  cent 

Hours 

Hours 

Hours 

L-19 

2 

0.399 

26.8 

0.8 

21.2 

8.0 

0.4 

7.0 

4 

.594 

39.7 

1.6 

31.7 

7.0 

.2 

6.0 

7 

.376 

22.4 

.9 

17.9 

7.0 

.2 

6.0 

25 

.429 

25.0 

.8 

19.9 

8.0 

.4 

7.0 

S-7 

5 

.371 

28.2 

1.6 

22.7 

8.5 

.3 

8.0 

6 

.370 

27.8 

2.0 

22.7 

8.3 

.3 

8.0 

7 

.371 

27.9 

1.4 

22.4 

8.3 

.3 

8.0 

8 

.362 

30.2 

1.8 

24.4 

8.3 

.3 

8.0 

S-4 

3 

.392 

29.5 

1.67 

23.8 

8.3 

.3 

8.0 

4 

.405 

30.3 

2.7 

25.2 

8.3 

.3 

8.0 

S-498 

1 

.333 

25.0 

.7 

19.8 

8.0 

.3 

5.0 

2 

.333 

25.0 

.7 

19.8 

7.0 

.3 

6.0 

S-502 

4 

.353 

26.5 

1.4 

21.4 

6.5 

.3 

6.0 

5 

.384 

28.8 

1.0 

22.9 

6.3 

.  3 

6.0 

6 

.428 

28.6 

1.0 

22.7 

9.3 

.3 

9.0 

7 

.441 

33.1 

1.3 

26.3 

9.5 

.3 

9.0 

8 

.431 

28.8 

1.1 

22.9 

9.3 

.3 

9.0 

S-39 

5 

.398 

29.9 

2.5 

24.6 

7.3 

.3 

7.0 

6 

.400 

30.0 

1.1 

23.9 

9.3 

.3 

9.0 

7 

.462 

34.7 

2.4 

28.2 

7.3 

.3 

7.0 

8 

.462 

34.7 

1.6 

27.8 

9.3 

.3 

9.0 

13 

.332 

22.2 

1.6 

18.1 

10.3 

.3 

10.0 

15 

.349 

26.2 

1.9 

21.4 

8.3 

.3 

8.0 

S-36 

3 

.477 

31.8 

1.5 

25.6 

5.5 

.3 

5.0 

4 

.481 

32.1 

1.8 

25.9 

6 . 5 

.3 

6.0 

5 

.477 

31.9 

1.5 

25.6 

9.5 

.3 

9 . 0 

6 

.326 

21.8 

1.0 

17.4 

12.3 

.3 

12.0 

7 

.343 

25.8 

1.4 

20.8 

12.3 

.  .3 

12.0 

L-105 

1 

.333 

25.0 

.7 

19.8 

7.0 

.3 

6 . 3 

2 

.333 

25.0 

.7 

19.8 

8.0 

.3 

7.0 

L-2 

1 

.333 

25.0 

.7 

19.8 

7.0 

.  3 

6.0 

S-469 

1 

.390 

29.4 

1.1 

23.3 

9.3 

.3 

y .  y 

2 

.367 

27.5 

1.0 

21.9 

10.3 

.3 

10.0 

S-499 

4 

.368 

27.6 

1.5 

22.3 

7.5 

.3 

7.0 

5 

.373 

28.0 

1.5 

22.5 

10.5 

.3 

10.0 

7 

.442 

29.5 

1.2 

23.6 

10.3 

.3 

10.0 

8 

.392 

26.2 

.9 

20.8 

12.3 

.3 

12.0 

L-3 

1 

.333 

25.0 

.8 

19.8 

7.0 

.5 

6.0 

2 

.266 

20.0 

.5 

15.8 

7.0 

.3 

6.0 

3 

.267 

20.0 

.5 

15.8 

8.0 

.3 

7.0 

.  S-524 

4 

.388 

25.9 

1.4 

20.9 

8.3 

.3 

8.0 

5 

.403 

26.9 

1.3 

21.6 

5.5 

.3 

5.0 

8 

.520 

34.7 

.9 

27.4 

4.3 

.3 

4.3 

9 

.534 

35.6 

1.8 

28.6 

6.3 

.  3 

6.0 

10 

.536 

35.8 

1.8 

28.7 

6.3 

.3 

6.0 

11 

.681 

45.4 

2.1 

36.5 

6.3 

.3 

6.0 

.  S-14 

2 

3 

.383 

.386 

25.6 

25.8 

1.4 

1.9 

20.6 

21.1 

8.3 

10.3 

.  3 
,3 

8.0 

10.0 

4 

.402 

26.8 

2.7 

22.4 

10.3 

.3 

10.0 

.  S-18 

1 

.434 

25.9 

1.5 

23.3 

8.3 

.3 

8 . 0 

2 

.387 

25.9 

1.5 

20.8 

10.3 

.3 

10.0 

.  L-26E 

18 

.333 

25.0 

.8 

19.9 

7.0 

.3 

6.0 

19 

.400 

30.0 

.8 

23.8 

7.0 

.3 

6  0 

.  S-16 

4 

.421 

28.1 

1.6 

22.8 

7.3 

.3 

i .  0 

5 

.427 

28.5 

2.0 

23.3 

10.3 

.  3 

10.0 

6 

.319 

23.7 

1.5 

19.2 

11.3 

.3 

11.0 

I .  S-38 

8 

.385 

25.7 

1.5 

20.8 

8.3 

.3 

8.0 

9 

.423 

28.2 

2.6 

23.4 

10.0 

1 .0 

8.0 

.  S-35 

4 

.346 

25.2 

.7 

19.9 

7.0 

.  3 

6.0 

MATERIALS  OF  PULP 

Record  of  Experimental  Cooks  Using  the  Soda  Process — Continued 


19 


Species 

Ship¬ 

ment 

number 

Cook 

num¬ 

ber 

Maxi¬ 

mum 

gauge 

pressure 

Yields 

Screened 

pulp 

Screen¬ 

ings 

Pounds 

• 

per  square 

inch 

Per  cent 

Per  cent 

Aspen . 

.  L-19 

2 

100 

50.3 

0.0 

4 

98 

46.5 

.0 

7 

100 

52.6 

.0 

25 

100 

50.8 

.0 

Beech . 

S-7 

5 

110 

50.7 

.1 

6 

110 

44.7 

.2 

7 

110 

45.4 

.8 

8 

110 

39.8 

1.0 

S-4 

3 

110 

4 

110 

43.7 

.1 

Douglas  fir . 

S-498 

1 

110 

45.3 

.1 

2 

100 

46.1 

..0 

Engelmann  spruce . 

S-502 

4 

110 

46.0 

1.0 

5 

110 

37.8 

.9 

6 

110 

39.4 

1.0 

7 

110 

36.2 

.1 

8 

110 

42.4 

.4 

Grand  fir . 

S-39 

5 

110 

41.7 

.1 

6 

110 

41.5 

.1 

7 

110 

41.6 

.1 

8 

110 

40.8 

.1 

13 

110 

46.0 

3.7 

15 

110 

47.9 

.5 

Incense  cedar . 

S-36 

3 

100 

38.6 

1.3 

4 

110 

39.5 

.2 

5 

no 

35.2 

.1 

6 

no 

41.7 

3.3 

7 

no 

36.3 

.2 

Jack  pine . 

L-105 

1 

100 

48.1 

.0 

2 

90 

51.8 

.1 

Loblolly  pine . 

L-2 

1 

no 

45.4 

.0 

Lodgepole  pine .... 

S-469 

1 

no 

38.1 

.1 

2 

no 

40.9 

.1 

S-499 

4 

no 

44.4 

.1 

5 

no 

39.0 

.2 

7 

no 

40.4 

.1 

8 

no 

42.1 

1.1 

Longleaf  pine . 

L-3 

1 

100 

48.6 

.0 

2 

100 

46.7 

4.4 

3 

100 

50.4 

.0 

Red  alder . 

S-524 

4 

no 

45.4 

.1 

5 

no 

48.7 

.1 

8 

no 

42.7 

.1 

9 

no 

38.2 

.1 

10 

no 

41.1 

.1 

11 

no 

39.1 

.1 

Red  ihaple . 

S-14 

2 

no 

44.6 

.2 

3 

no 

4 

no 

42.6 

.3 

Sycamore . 

S-18 

1 

no 

43.4 

.1 

.  2 

no 

45.4 

.2 

Tamarack . 

L-26E 

18 

no 

35.0 

8.7 

19 

no 

37.8 

.0 

Tulip  tree . 

S-16 

4 

no 

42.2 

.0 

5 

no 

40.7 

.  1 

6 

no 

40.5 

.  1 

Western  hemlock . . 

S-38 

8 

no 

45.7 

.8 

9 

no 

42.6 

1.0 

White  fir . 

S-35 

4 

100 

49.0 

4.7 

Quality  of  pulps 


Ash 


Bleach 

required 


Loss  on 
bleaching 


Per  cent 

0.81 

.95 

.85 

.79 

.73 

.76 

.78 

.92 

1.51 

1.73 


.71 

.82 

.69 

.71 


.52 

.60 

.66 

.59 


.96 

.78 

.73 

1.05 

.69 


.64 

.90 

.82 

.87 

.73 


.76 

.77 

.69 

.71 

.66 

.87 

.91 

.63 

.78 

1.08 

1.27 


.85 

1.01 

.98 


Per  cent 

8.0 

6.0 

9.0 

9.5 

13.2 

15.3 
14.7 


23.2 

26.5 


93.0 

67.0 

69.0 

42.5 


63.0 

46.0 

47.5 

44.6 


90.0 

80.0 


41.0 

51.5 
46.0 
41.0 

46.5 


23.8 

25.5 

20.8 
20.1 

18.5 
18.0 

15.5 
13.0 
12.4 
13.7 
15.0 


15.0 

14.1 

18.8 


66.4 


Per  cent 

1.1 

.4 

1.6 

1.4 

2.1 

1.8 

3.0 


1.5 

1.7 


7.4 

8.2 

4.9 


6.1 

4.8 

8.9 
4.4 


9.1 


4.6 


5.4 

5.4 

5.5 


3.2 

3.5 

2.5 
2.8 
2.8 

2.3 

2.6 


3.2 


3.0 

2.4 

3.1 


MODERN  PULP  AND  PAPER  MAKING 


The  esparto  is  shipped  in  bales,  from  which  the  ropes  and 
hoops  have  first  to  be  removed.  The  bundles  are  then  treated  in 
a  machine  like  a  rag  duster  which  breaks  them  up  and  frees  them 
from  dirt. 

According  to  Clapperton  ^  from  4,000  to  pounds  of 

esparto  can  be  boiled  in  from  2>4  to  3  hours,  under  a  pressure  of 
from  30  to  40  pounds,  using  14  to  16  per  cent  of  70  per  cent 
caustic  soda  on  the  raw  material. 

Preparing  Straw  for  Bleached  Pulp. 

The  straw  is  digested  with  caustic  soda  under  pressure,  yield¬ 
ing,  when  bleached,  a  white  paper  pulp  which  is  nearly  pure  cellu¬ 
lose.  The  fibres  are  very  fine  and  shorter  than  those  obtained 
from  wood,  but  very  strong.  Such  material  imparts  to  paper  a 
certain  hardness  and  “rattle”  that  is  distinctive  of  fine  writing 
papers. 

The  following  is  the  composition  of  various  straws,  according 
to  Muller : 

Winter  Winter  Summer  Winter  Oats 


Rve  Wheat  Barley  Barley 

%  %  %  %  % 

Water. .  i4-3  H-S  H-S  i4-3  i4-3 

2 Total  organic  material .  82.5  80.2  79-7  80.2  80.7 

Ash .  3-2  5-5  •••■  5-5  S-O 

Cellulose .  54-0  480  43.0  48.4  40.0 


Rye  straw  is  the  first  choice,  then  wheat  and  lastly  oat  straw. 
The  straw  is  carefully  picked  over  for  the  removal  of  all  im¬ 
purities,  such  as  weeds,  roots,  etc.  This  picking  is  done  by  hand, 
the  straw  being  spread  on  a  long  table  at  which  are  seated  the 
workers.  When  the  picking  is  completed  the  straw  is  cut  into 
pieces  from  two-fifths  of  an  inch  to  one  inch  in  length  by  means 
of  a  straw  cutter  which,  according  to  the  extent  of  the  operations 
at  the  mill,  is  capable  of  turning  out  from  600  to  2,500  pounds 
hourly.  The  cut  straw  is  freed  from  any  grain,_  nodes  or  sand  it 
may  contain  by  means  of  a  gentle  current  of  air  produced  by  a 
fan.  The  nodes  of  the  straw  do  not  contain  any  fibres  and  are 
very  hard,  being  composed  chiefly  of  insoluble  siliceous  matter. 
Consequently  it  is  necessary  to  remove  them  so  they  cannot  pass 
into  the  digesters  as  they  absorb  a  good  deal  of  soda,  render 
bleaching  difficult,  stain  the  pulp  and  reduce  its  value.  In  some 
mills  handling  esparto  and  straw  the  material  is  charged  into  the 
digesters  without  being  cut,  but  this  is  oldei  and  less  efficient 

^  For  boiling  it  is  customary  to  use  rotary  horizontal  or  spherical 
digesters.  Sometimes  stationary  vertical  digesters  are  used._  The 
spherical  digesters  are  better  than  the  cylindrical  ones,  as  in  the 
latter  there  is  danger  of  the  straw  forming  a  compact  mass  unless 
special  interior  arrangements  are  provided,  and  these  are  trouble- 

1  Practical  Paper  Making.  London,  1917- 

2  Includes  cellulose. 


21 


MATERIALS  OF  PULP 

some.  One  of  these  devices  is  a  system  of  bars  riveted  to  the 
wall,  but  repairs  to  these  bars  are  difficult,  and  moreover  they 
interfere  with  loading  and  unloading  the  digester. 

The  usual  capacity  of  the  digesters  is  2,000  pounds  of  cut 
straw.  The  straw  is  introduced  through  a  manhole  by  manual 
labor,  or  else  by  means  of  a  blower.  The  mass  is  then  treated 
with  caustic  soda  solution  of  from  10  to  15  per  cent  strength  at  a 
temperature  of  from  140°  F.  to  150°  F.  In  the  English  mills 
the  usual  practice  is  to  use  16  pounds  of  caustic  per  112  pounds 
of  raw  material  and  to  digest  from  one  and  a  half  to  two  houis 
at  40  pounds  pressure.  In  American  mills  the  pressures  vary 
from  10  to  50  pounds,  and  the  duration  of  the  operation  from  one 
and  one-half  to  five  hours.  The  heat  and  pressure  is  supplied  by 
the  injection  of  direct  steam. 

When  the  boiling  is  complete,  the  digester  is  emptied.  Some¬ 
times  this  is  done  through  a  manhole  and  sometimes  the  pulp  is 
blown  into  a  washing  machine  similar  to  a  beater  where  it  is  both 
beaten  and  freed  from  chemicals. 

The  further  treatment  of  the  pulp  is  practically  the  same  as 
in  the  manufacture  of  soda  pulp  from  wood,  which  is  described 
fully  in  a  subsequent  chapter.  The  soda  liquor  is  also  recovered 
in  the  same  way. 

Esparto  is  sometimes  pulped  by  a  modified  sulphate  process, 
instead  of  by  the  soda  process  above  described.  In  this  way  a 
pulp  is  made  the  value  of  which  for  high  class  printing  and  me¬ 
dium  quality  writing  papers  is  well  known.  This  material  has 
qualities  that  cannot  readily  be  obtained  from  other  fibres  such 
as  rag  and  wood  pulp.  It  is  chiefly  used  in  papers  intended  for 
lithographic  printing,  books,  etc.,  and  other  purposes  where  a 
sheet  is  demanded  which  must  have  a  good  surface  and  yet  be 
soft  and  pliable. 

Straw  Board. 

The  following  is  a  description  of  the  treatment  of  straw  to 
make  pulp  for  strawboard : 

The  straw  is  subjected  to  a  cooking  process  with  steam  and 
milk  of  lime  in  large  ellipsoidal  rotary  digpters.  The  digester  is 
filled  with  straw  and  liquor,  steam  admitted,  the  mass  cooked 
down  and  then  more  straw  and  liquor  put  in  until  the  maximum 
capacity  of  the  digester  is  reached.  The  final  charge  consists  of 
about  6  tons  of  straw  and  2,100  pounds  of  lime  in  the  form  of 
milk  of  lime.  The  mixture  is  then  rotated  under  40  pounds 
steam  pressure  for  12  hours.  By  this  process  the  straw  is  reduced 
to  a  dark-yellow,  pulpy  mass.  The  yield  of  pulp  is  frorn  75  to 
80  per  cent  of  the  original  material.  The  stock  from  the  digesters 
is  stacked  in  pits  and  allowed  to  drain  for  24  hours  or  more.  It 
contains  practically  all  the  lime  and  about  50  per  cent  of  water. 

The  stock  is  then  placed  in  a  washing  machine,  similar  to  that 
used  in  making  rag  pulp,  only  somewhat  cruder  in  design.  It 


22 


MODERN  PULP  AND  PAPER  MAKING 


contains  a  beater  roll  and  bed  plate  and  a  revolving  brass  screen 
through  which  the  water  escapes  carrying  the  lime  in  solution 
together  with  the  finer  particles  of  fiber. 

After  the  washing  is  complete  the  stock  is  conducted  to  a  kind 
of  cylinder  machine,  similar  to  the  cylinder  paper  machine  de¬ 
scribed  in  another  chapter,  and  formed  into  strawboard  or  paste¬ 
board. 


Fig.  I. — Type  of  rotary  digester  used  in  strawboard  industry. 
Bamboo. 

The  British  have  displayed  great  interest  in  bamboo,  because 
there  are  in  the  British  Isles  no  forests  suitable  for  supplying 
wood  for  wood  pulp,  and  consequently  British  paper  makers  have 
been  somewhat  more  inclined  than  others  to  investigate  new  ma¬ 
terials.  In  the  British  tropical  possessions  there  are  unlimited 
supplies  of  bamboo. 

These  investigations  are  of  some  interest  in  this  country,  as 
in  the  southern  Atlantic  states  there  are  quantities  of  canes  very 
similar  to  the  bamboo  that  may  have  to  be  used  for  paper  in  the 
future. 

As  long  ago  as  1875  Rutledge^  (who  introduced  esparto  into 
England)  advocated  the  use  of  bamboo.  About  1906  R.  W. 
Sindall  made  a  very  thorough  invetigation  of  the  subject  for  the 

^  Rutledge  had  his  original  pamphlet  printed  on  paper  made  from  bamboo. 


MATERIALS  OF  PULP 


23 

British  Government.  Since  then  actual  manufacturing  operations 
have  been  carried  on  in  India  and  in  the  Philippines. 

The  stems  are  cut  in  such  a  manner  that  the  nodes  are  re¬ 
jected.  In  India  the  cook  is  carried  out  at  60  pounds  pressure 
for  10  hours  with  30  pounds  of  76  per  cent  caustic  per  100  pounds 
of  dry  bamboo.  Bleach  is  used  in  the  proportion  of  20  pounds 
per  100  pounds  of  pulp. 

The  bamboo  has  also  been  worked  up  in  Burmah  by  the  sul¬ 
phite  process  at  a  cost  of  about  $24.00  per  ton,  the  yield  being 
over  50  per  cent  and  less  bleach  being  required  than  with  the 
soda  process  described  above. 

In  the  Philippines  the  soda  process  has  been  used,  from  40  to 
43  per  cent  of  bleached  fiber  being  obtained. 

Paper  made  from  bamboo  is  excellent  for  book  and  writing 
purposes.  An  interesting  point  about  bamboo  is  the  fact  that 
once  cut  it  grows  again  "very  rapidly.  On  a  conservative  estimate 
only  about  16  square  miles  would  be  required  to  supply  a  loo-ton 
mill  indefinitely.  The  chief  reason  bamboo  has  not  been  used 
more  is  that  the  lands  where  it  is  indigenous  are  so  far  from  the 
great  paper  markets. 

Jute. 

Jute  is  received  in  the  paper  industry  in  the  form  of  old  gunny 
sacks  and  rope  and  also  as  jute  cuttings,  which  are  the  parts  of 
the  plant  rejected  in  making  jute  fabrics. 

According  to  Muller  raw  jute  fibre  contains  63.76  per  cent 
cellulose  and  the  jute  cuttings  contain  about  60.89  per  cent. 

Jute  fibre  is  strong  and  suitable  for  many  kinds  of  paper.  It 
cannot  be  used  in  fine  papers  on  account  of  the  great  difficulty  in 
bleaching  it.  So  much  bleach  has  to  be  used  to  render  it  white 
that  all  advantage  gained  through  cheapness  in  the  original  ma¬ 
terial  is  lost  and  also  the  strength  of  the  fibres  is  weakened  by 
the  large  amount  of  bleach. 

Jute  materials  are  generally  boiled  with  lime,  sometimes  some 
caustic  soda  being  added.  The  equipment  used  and  the  general 
conduct  of  the  process  are  the  same  as  described  for  rags. 

Manila,  Hemp,  Etc. 

Manila  hemp  is  a  fibre  produced  in  the  Philippines,  which  is 
of  interest  as  being  the  original  source  of  the  class  of  papers 
known  as  Manilas,  which  are  very  desirable  for  wrapping  and 
for  other  purposes,  being  very  smooth,  clean,  soft  and  flexible, 
taking  an  excellent  and  characteristic  finish,  and  being  quite 
strong  at  the  same  time. 

According  to  Muller  Manila  contains  64.07  per  cent  cellulose. 
Many  of  the  Manila  papers  on  the  market  today  contain  none  of 
this  fibre  at  all,  being  clever  imitations. 

Other  varieties  of  hemp,  siich  as  Italian  Hemp,  Sunn  Hemp, 
etc.,  are  sometimes  used  as  raw  materials  for  paper,  generally  in 


24  MODERN  PULP  AND  PAPER  MAKING 

the  form  of  discarded  fabrics  or  cordage.  When  hemp  is  spoken 
of,  Italian  Hemp  (Cannabis)  is  usually  meant. 

Agave  fibre,  of  which  Sisal  Hemp  is  one  well  known  form,  is 
largely  used  in  rope  and  cord,  and  in  this  form  it  reaches  certain 
types  of  paper  mill.  This  plant  is  a  native  of  tropical  America. 

Rags. 

At  one  time  rags  formed  the  only  raw  material  of  paper.  Of 
recent  years  the  importance  of  this  kind  of  paper  stock  ^  has 
steadily  been  decreasing,  and  with  the  more  extensive  use  of  other 
kinds  of  pulp  only  minor  importance  is  attached  to  the  prepara¬ 
tion  of  rag  pulp,  in  America,  at  least.  However,  at  the  present 
time  rags  to  the  value  of  about  $12,000,000  annually  are  used  for 
paper  making,  chiefly  in  the  more  expensive  grades  of  paper, 
such  as  paper  used  for  fine  writing  purposes,  fine  books,  the  print¬ 
ing  of  stock  certificates,  bonds,  money  and  legal  documents,  etc., 
where  fine  finish  and  permanency  are  the  object  and  where  ex¬ 
pense  is  not  an  objection,  and  (in  the  case  of  cheap  rags)  in  such 
specialities  as  roofing  paper,  and  consequently  the  subject  merits 
some  discussion. 

The  word  “rag”  is  used  to  designate  a  very  wide  range  of  raw 
material  for  conversion  into  paper.  The  prices  which  various 
kinds  of  rags  bring  vary  very  widely  according  to  their  suitability 
for  various  kinds  of  paper.  Naturally  those  rags  which,  with 
the  minimum  of  treatment,  constitute  suitable  raw  material  for 
the  highest  grades  of  writing  paper,  bring  the  best  prices.  The 
following  table  taken  from  one  of  the  trade  papers,  shows  how 
carefully  this  class  of  material  is  graded  and  the  range  of  prices. 
It  will  be  noted  that  white  rags  bring  considerably  more  than  col¬ 
ored  ones,  and  clean  rags  more  than  soiled.  Unsorted  rags  bring 
much  lower  prices  than  sorted  rags  because  the  paper  maker  does 
not  want  a  mixture  of  old  and  new  rags,  clean  and  dirty,  or  white 
and  colored  in  the  same  lot.  They  also  must  be  sorted  by  ma¬ 
terials.  Cotton  rags  must  not  Te  mixed  with  linen  or  hemp,  etc. 

In  the  case  of  high  class  writing  papers,  only  the  best  quali¬ 
ties  are  considered,  such  as  new  linen  and  cotton  cuttings,  or  well 
sorted  rags  of  domestic  origin.  However,  the  majority  of  rags 
used  in  the  paper  industry  are  more  or  less  foul  and  require  some¬ 
what  drastic  treatment. 

Sorting.  The  first  operation  involved  is  that  of  sorting,  either 
done  by  hand  or  mechanically.  Different  materials  are  sorted 
from  each  other.  Different  colors  are  sorted  out.  Buttons,  pins, 
etc.,  are  removed.  Notwithstanding  the  increased  cost  of  sorting 
by  hand,  and  the  objection  to  it  on  account  of  the  danger  to  the 

1  The  term  “paper  stock”  is  applied  in  the  trade  to  a  large  variety  of  materials 
used  for  making  paper.  It  applies  generally  to  waste  material,  whether  paper,  rags, 
cotton,  linen,  jute,  hemp,  flax  or  Manila.  It  may  come  in  the  form  of  new  clippings 
from  the  fabrics  made  of  the  various  fibres  or  old  pieces  of  the  same,  or  may  come 
in  the  forni  of  threads,  strings,  twines  or  ropes,  or  in  the  form  of  waste  of  various 
qualities,  such  as  card  waste,  rove  waste,  washed  flax  waste,  etc.  Manufacturers  of 
roofing  and  felt  paper  use  many  thousands  of  tons  of  such  miscellaneous  material  each 
year,  much  of  it  being  of  foreign  origin. 


MATERIALS  OF  PULP 


25 


COMMERCIAL  GRADES  OF  RAGS 
From  “The  Paper  Industry,"  June,  1920 


New  Stock — 

White  shirt  cuttings,  No.  i 
White  shirt  cuttings,  No.  2 

Fancy  shirt  cuttings . 

Washables,  No.  i . 

Unbleached  muslins . 

White  lawns . . 

Overall  cuttings,  blue . 

Black  Silesias . 


New  York  and  Chicago 

.  19.50-20.00 

• .  13  00-13.50 

.  12.50-13.00 

.  10. 50-1 I. 00 

.  16.00-16.50 

.  17.50-18.00 

.  13.00-13.50 

.  7 . 50-  8 . 00 


Old  Stock — 

Whites,  No.  i  repacked .  14.00-16.00 

Whites,  No.  2  repacked .  7 -50-  8.00 

Whites,  house  soiled .  4 . 50-  4 . 75 

Whites,  street  soiled .  4  25-  4. 50 

Thirds  and  blues,  repacked .  4  •  75~  5  ■  00 

Thirds  and  blues,  rough .  4.00-  4.25 

Black  stockings . . .  ■: .  4 . 60-  4 . 80 

Lace  curtains .  9  25-  9.50 

Cotton  canvas,  No.  i .  5-50-  6.00 

White  cotton  batting .  5.0c-  5.25 

Roofing,  No.  I .  3  -25-  3 -50 

Roofing,  No.  2 .  3  15-  3  -25 


health  of  the  workers,  this  plan  is  generally  conceded  to  be  the 
best  in  the  end,  especially  for  the  better  grades  of  paper,  as  more 
thorough  sorting  and  removal  of  impurities  result. 

Dusting.  Following  this  operation  of  sorting  and  cutting,  is 
that  of  dusting,  which  is  done  mechanically.  One  machine  for 
doing  this  is  a  rag  “willow,”  which  takes  the  material  to  be  treated 
through  a  hopper  into  a  compartment  where  a  revolving  cast-iron 
cone,  armed  with  spiral  flanges  bearing  pins,  passes  it  rapidly  and 
regularly  to  the  discharge  opening.  This  process  opens  up  the 
material,  separates  the  dust  from  it  and  does  this  without  such 
violent  treatment  as  to  cause  injury  to  the  fibres. 

The  case  is  of  wood,  with  cast-iron  ends  containing  the  bear¬ 
ings.  Tight  and  loose  pulleys  comprise  the  drive,  which  turns 
the  cone  at  300  revolutions  per  minute.  Over  the  ends  of  the  cone 
are  the  cast-iron  collars  of  the  lid,  neatly  fitting  in  order  to  pre¬ 
vent  the  escape  of  dust.  In  the  center  of  the  lid  at  the  top  is  a 
steel  plate  containing  pins  which  permit  those  on  the  cone  to  pass 
between,  thus  opening  up  the  stock  .  Below  the  cone  is  a  bottom 
of  wire  through  which  the  dust  sifts  and  is  removed  by  swing¬ 
ing  doors  at  the  side.  The  floor  space  occupied  by  such  a  machine 
is  about  3  feet  by  6  feet. 

Rag  Thrashers  are  similar  in  effect  to  willows.  One  type  of 
thrasher  consists  of  a  wooden  case  in  which  a  horizontal  octagonal 
drum  revolves  at  a  speed  of  about  120  revolutions  a  minute. 
This  drum  is  armed  on  two  opposite  sides  with  heavy  teeth  bound 


I 


26 


MODERN  PULP  AND  PAPER  MAKING 


by  iron  and  filled  with  wood.  These  play  between  corresponding 
teeth  which  are  planted  in  a  beam  fastened  to  the  top  of  the  case. 
Below  the  drum  is  a  wire  cloth,  through  which  the  dust  falls  as 
a  combined  result  of  thrashing  the  rags  between  the  two  sets  of 
teeth  and  vigorously  moving  them  over  the  wire  itself.  The  drive 
•  consists  of  two  loose  pulleys,  between  which  is  run  a  tight  one. 
Belts,  giving  right  and  left  rotation,  run  upon  the  loose  pulleys 
until  either  belt  is  moved  to  the  tight  pulley.  One  manufacturer 
of  such  machines  states  that,  when  attended  by  one  man,  one  of 
them  will  thrash  from  800  to  1,000  pounds  of  cotton  rags  per 
hour,  and  that  the  actual  loss  of  weight  from  the  time  the  rags 
are  taken  from  the  bale  until  they  have  passed  through  the  rag 
cutters  is  15  per  cent. 


Courtesy:  The  Pusey  &•  Jones  Co.,  WiPnington,  Del. 

Fig.  la.— Typical  rag  willow. 

Rag  dusters  are  generally  built  of  hardwood  boards  firmiy 
bolted  together  and  reinforced  at  points  of  wear  by  iron  castings. 
In  the  center  is  a  wooden  drum  15  inches  in  diameter,  bolted  to 
cast-iron  spiders,  which  are  in  turn  keyed  to  a  shaft,  designed  to 
turn,  by  means  of  tight  and  loose  pulleys,  at  100  revolutions  a 
minute.  Fastened  to  the  drum  is  a  series  of  steel  plates  set  at 
such  an  angle  as  to  insure  the  traveling  of  the  rags  from  the 
inlet  to  the  discharge  end.  In  doing  so  they  are  thrown  open  and 
blown  free  from  dust. 

Cutting.  A  rag  cutter  consists  of  an  iron  table  bolted  on  the 
top  of  a  heavy  cast-iron  stand.  This  table  supports  the  bearings 
of  the  two  driving  shafts.  To  one  of  these  shafts,  driven  by  a 


MATERIALS  OF  PULP 


27 


tight  and  loose  pulley,  a  cutter  head  is  attached,  which  carries 
three  fly  knives  firmly  bolted  within  heavy  cast-steel  shoulders. 
At  the  other  end  of  this  shaft  is  a  fly  wheel  to  relieve  the  shock 
when  cutting.  The  bed  knife  is  contained  in  the  table  and  is  held 
by  both  adjusting  and  tightening  bolts. 

A  separate  belt,  on  a  small  pulley  to  the  right  of  the  operator, 
propels  a  series  of  gears  which  drive  a  drum  studded  with  projec¬ 
tions  set  in  rows  and  staggered.  This  drum  spreads  the  feed  of 
rags  to  the  knives  and  serves  as  a  protection  to  the  operator.  It 
is  carried  on  a  curved  frame,  which  may  be  lifted  by  the  operator 


Courtesy :  The  Pusey  S’  Jones  Co.,  Wilmington,  Del. 

Fig.  ib. — Typical  rag  cluster. 


by  means  of  a  lever  to  ease  the  passage  of  rags,  should  they  get 
choked  in  the  feed  trough. 

The  length  of  the  rag  cut  may  be  controlled  by  a  difference  of 
speed  imparted  to  the  two  belts. 

Boiling.  After  all  this  mechanical  treatment,  the  rags  are 
ready  to  be  boiled.  The  boiling  is  usually  done  in  vessels  of  steel 
plate  which  may  be  of  spherical,  cylindrical  or  vomiting  types. 
The  object  of  the  boiling  is  to  remove  the  grease  and  dirt  and  by 
means  of  the  high  temperature,  the  agitation  and  the  chemicals 
used,  bring  the  rags  into  such  condition  that  the  impurities  can 
readily  be  removed  by  washing,  leaving  fibre  suitable  for  paper. 

d'he  rotary  boilers  commonly  employed  are  of  cylindrical 
readily  be  removed  by  washing,  leaving  fiber  suitable  for  paper. 
The  trunnions  are  of  cast  iron  or  steel  and  are  firmly  attached  to 
the  boiler  by  large  flanges,  in  some  cases  these  flanges  serving 


28  MODERN  PULP  AND  PAPER  MAKING 

as  the  head  of  the  boiler.  The  trunnions  are  hollow  for  the  ad¬ 
mission  of  steam.  Manholes  are  provided  for  filling  and  empty- 
ing. 

In  some  cases  ribs  or  projections  are  arranged  around  the  in¬ 
side  to  prevent  the  stock  packing  against  the  sides.  The  boilers 
are  supported  on  steel,  masonry  or  wooden  supports,  as  may  be 


Courtesy :  The  Pusey  &  Jones  Co.,  Wilmington,  Del. 

Fig.  ic.^ — Rag  Cutter. 

required  and  are  driven  by  means  of  worm  gearing  countergeared 
to  suit  conditions.  The  usual  speed  at  which  they  rotate  is  from 
to  3  revolutions  per  minute.  The  usual  sizes  are  from  6  by  lo 
feet  (capacity  270  cu.  ft.)  to  8  by  24  feet  (capacity  995  cu.  ft.). 
The  internal  pressures  used  vary  from  60  to  120  pounds. 

The  chemical  usually  added  in  America  is  milk  of  lime.  In 
England  caustic  soda  is  chiefly  used.  The  lime  forms  soaps  with 
the  grease  in  the  rags  and  is  not  a  sufficiently  strong  alkali  to 
damage  the  fibre  as  soda  is  prone  to  do.  Sometimes  a  little  soda 
is  added  to  increase  causticity  of  the  solution.  In  some  cases,  rags 
are  boiled  with  soda  alone,  but  this  is  unusual.  The  usual  prac¬ 
tice  is  to  fill  the  rotary  about  two-thirds  full  with  rags  and  milk 
of  lime  and  run  for  from  twenty  minutes  to  half  an  hour  before 
steam  is  admitted.  The  lime  used  for  this  purpose  should  he 


MATERIALS  OF  PULP 


29 

ascertained  to  be  free  from  iron  before  being  used  as  iron  will 
discolor  the  stock,  and  should  also  be  free  from  gritty  material 
such  as  sand  and  coal  dust.  The  amount  of  lime  used  varies. 
About  15  per  cent  of  lime  based  on  the  dry  weight  of  the  rags 
is  quite  a  usual  proportion  but  as  high  as  20  per  cent  and  some- 


Courtesy ;  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  2. — Two  typical  rag  boilers. 


times  as  low  as  4  per  cent  is  used.  The  higher  grades  of  rags 
require  less  lime  and  also  lower  temperature  and  pressure  and  a 
shorter  boiling  period.  However,  this  also  depends  largely  on  the 
kind  of  paper  being  made.  Conditions  have  to  be  determined 
by  experiment  at  each  mill. 

Various  practices  prevail  with  regard  to  emptying  the  ro- 


30  MODERN  PULP  AND  PAPER  MAKING 

taries.  Some  operators  relieve  all  the  pressure  before  removing 
the  stock.  Others  blow  off  under  pressure  just  as  in  a  sulphite 
'digester.  This  latter  procedure  is  hard  on  the  stock,  but  it  is 
claimed  it  gets  rid  of  more  dirt. 

The  rags  are  generally  drained  on  draining  floors  or  in  shallow 
pits.  Sometimes  they  are  let  stand  some  days  after  boiling  to 
soften. 

A  device  known  as  a  Mather  Kier  is  frequently  used  for  rag 
boiling,  especially  in  England,  instead  of  a  rotary  boiler.  It  con¬ 
sists  of  a  sort  of  tank  into  which  cars  can  be  run  containing  the 
rags.  There  is  a  device  for  spraying  the  hot  liquid  over  the  rags. 
The  advantages  claimed  are  saving  in  steam  and  floor  space,  im¬ 
proved  quality  of  fibre  and  saving  in  quantity  of  water  used  for 
washing. 

Vomiting  boilers  are  sometimes  used.  These  are  cylindrical 
stationary  tanks  in  which  the  steam  is  conducted  to  the  bottom 
through  a  pipe  which  enters  through  the  top  of  the  boiler.  This 
steam  forces  the  liquid  which  has  collected  beneath  a  false_  bot¬ 
tom  upwards,  through  a  vomit  pipe  surrounding  the  steam  inlet, 
and  it  is  sprayed  over  the  stock  by  a  spreader.  There  are  man¬ 
holes  for  filling  and  emptying  and  a  safety  valve.  This  is  quite 
like  the  ordinary  domestic  coffee  percolator. 

Washing.  Following  the  boiling  of  the  rags  comes  the  wash¬ 
ing  to  remove  all  alkali  used  in  the  cooking,  as  well  as  all  dirt 
and  greases  that  were  loosened  during  the  chemical  treatment. 
This  washing  is  usually  performed  in  a  rag  engine  or  Hollander. 
This  machine  is  similar  to  the  beater  or  beating  engine  (which 
is  described  in  detail  in  Chapter  XII)  except  that  on  the  side  of 
the  midfeather  opposite  the  beater  roll  is  a  revolving  cylinder  or 
octagon  covered  with  wire  cloth.  This  permits  the  wash  water 
to  run  through  but  keeps  the  fibres  in  the  machine.  There  may 
be  more  than  one  of  these  cylinder  washers;  in  some  machines 
as  many  as  four  or  five  are  used.  Sand  catchers  are  usually 
inserted  in  the  base  of  the  engine  in  front  of  the  roll  to  catch 
dirt,  buttons,  etc.,  in  the  stuff.  In  this  way  the  machine  serves  not 
only  the  purpose  of  a  beater,  breaking  up  the  bundles  of  fibres  and 
drawing  them  out,  but  also  permits  all  alkali  and  impurities  to  be 
carried  away  with  the  wash  water.  In  some  mills  machines  are 
used  having  a  paddle  in  place  of  a  beater  roll.  This  propels  the 
stock  around  the  machine  but  does  not  break  up  the  fibre  bundles 
or  brush  out  the  fibres,  all  of  this  work  being  left  for  the  regular 
beaters  in  which  the  stock  is  placed  after  bleaching. 

The  clean,  washed  and  disintegrated  rag  stock  is  now  bleached, 
either  by  means  of  bleaching  powder  or  electrolytic  bleach 
(bleaching  will  be  dealt  with  fully  in  Chapter  XI),  after  which 
it  is  thoroughly  washed  to  remove  any  excess  of  bleach  remaining. 

The  rag  stock  at  this  point  is  known  as  “half  stuff,”  and,  in 
order  to  convert  this  half  stuff  into  paper,  it  must  be  further 
Treated  in  beaters  or  beating  engines  to  obtain  a  complete  separa- 


Materials  of  pulp  31 

tion  of  the  fibres  into  single  units  and  to  stroke  out  the  fibres  so 
they  will  felt  and  form  paper,  as  explained  in  detail  in  Chapter 
XII. 

Bagasse. 

Of  all  the  different  materials  investigated  during  the  last  few 
years,  during  which  period  millions  of  dollars  have  been  spent 
to  advance  the  art  of  cellulose  utilization,  few  materials  have  re¬ 
ceived  more  attention  than  bagasse,  the  residue  of  sugar  cane 
after  the  juice  has  been  pressed  from  it. 


Courtesy:  Dowiiigtown  Manufacturing  Co.,  East  Dowingtown,  Pa. 


Fig.  3. — Hollander  or  washing  engine,  as  used  in  manufacture  of  rag 
paper,  showing  cylinder  washer. 


Before  the  introduction  of  a  process  whereby  this  waste  could 
be  utilized  for  paper  pulp  it  was  piled  and  burned  in  the  furnaces 
of  the  sugar  mills.  It  has  been  found  that  the  bagasse  contains 
fibres  of  a  high  quality  suitable  for  many  grades  of  paper.  The 
sugar  cane  stalk  is  largely  composed  of  two  constituents,  fibrous 
cellulose  and  non-fibrous  cellulose  in  about  equal  parts.  A  proc¬ 
ess  is  now  being  investigated  whereby  these  two  constituent  parts 
can  be  separated  mechanically  and  the  fibre  treated  chemically 
either  by  the  soda  or  the  sulphite  process.  Bagasse  boards  are 
manufactured  in  Louisiana  by  the  Lee  process  in  which  the  ba¬ 
gasse  is  digested  with  a  liquor  prepared  by  treating  low  grade 
molasses  from  the  sugar  mills  with  lime,  its  principal  constituent 
being  saccharate  of  lime.  The  boiling  causes  a  hydration  of  the 
non-fibrous  cellulose  which  toughens  it  and  thus  makes  it  possible 
to  make  pulp  out  of  material  that  really  hardly  contains  any  fibers 
at  all,  the  cells  of  the  non-fibrous  cellulose  being  too  short  to  cor¬ 
rectly  be  called  fibres. 


32  MODERN  PULP  AND  PAPER  MAKING 

Interesting  experiments  have  also  been  carried  out  on  making 
semi-transparent,  glassine  and  parchment  papers  from  bagasse  by 
utilization  of  this  hydration  effect. 

Waste  Flax  Fibre. 

Some  work  has  been  done  on  the  utilization  of  this  material 
for  paper.  The  fiber  would  be  of  excellent  quality  for  making 
high  grade  papers,  provided  that  it  could  be  obtained  entirely  free 
of  seeds  which  make  grease  spots  in  the  stock  and  defects  in  the 
paper.  Up  to  date  this  has  been  the  chief  obstacle.  It  has  been 
estimated  by  the  U.  S.  Government  that  sufficient  of  this  material 
is  now  wasted  annually  in  the  Northwestern  States  to  make  480,- 
000  tons  of  good  paper. 

In  connection  with  the  above  remarks  on  various  of  the  new 
materials  proposed  for  paper,  the  following  table  ^  may  be  of 
interest : 


Estimates  of  Wastes  Suitable  for  Paper  Making  Produced  Annually 


Waste 

Yield  of 

Material 

Quantity 

(Tons) 

Value 

$ 

Paper 

(Tons) 

Waste  textiles  suitable  for  papers  of  the  highest 
quality  and  strength . 

1,000,000 

20,000,000 

800,000 

Flax  fiber  suitable  for  the  best  and  strongest 
paper . 

600,000 

18,000,000 

480,000 

Forest  waste  from  lumber  industry  suitable  for 
medium  and  low  grade  paper . 

U2,000,000 

60,000,000 

5,000,000 

Waste  paper  suitable  for  high  quality  and  lowest 
quality . 

1,000,000 

10,000,000 

900,000 

Cereal  straws  suitable  for  medium  quality  paper 
and  boards . 

70,000,000 

350,000,000 

28,000,000 

1  Cords. 


Waste  Paper. 

According  to  U.  S.  Government  statistics  more  than  6,000,000 
tons  of  paper  are  now  made  annually  in  this  country,  of  which 
fully  80  per  cent,  or  4,800,000  tons,  becomes  waste  material  in 
three  or  four  years.  Of  this,  about  25  per  cent,  or  1,200,000  tons, 
is  again  used  in  the  form  of  cuttings  and  trimmings  and  old  paper 
for  making  new.  While  there  must  always  be  some  waste  im¬ 
possible  to  recover,  with  proper  precautions  a  much  larger  per¬ 
centage  could  be  recovered  than  is  now  the  case.  The  recent  war 
has  given  a  considerable  impetus  to  the  saving  and  utilization  of 
waste  paper. 

Not  all  waste  paper  is  suitable  for  the  manufacture  of  high 

*  U.  S.  Department  of  Agriculture,  Bureau  of  Chemistry.  Circular  No.  41 


MATERIALS  OF  PULP 


33 


grade  papers,  such  as  book,  but  almost  all  of  it  can  be  worked  up 
into  some  kind  of  wrapping,  cover  or  blotting  paper,  building  pa¬ 
per,  boards,  etc. 

The  principal  difficulty  in  getting  satisfactory  results  in  an  at¬ 
tempt  to  substitute  waste  paper  for  chemical  or  mechanical  wood 
pulp  consists  in  the  fact  that  the  equipment  of  the  average  mill 
does  not  lend  itself  readily  to  such  substitution.  Beaters  which 
are  most  efficient  in  treating  rags,  bagging,  rope,  sulphite,  etc., 
are  not  well  adapted  to  the  treatment  of  waste  paper.  It  must  be 
borne  in  mind  that  waste  papers  have  all  been  once,  at  least, 
through  the  process  of  manufacture  of  paper.  Hence,  it  is  only 
reasonable  to  assume  that  such  grinding,  beating  and  brushing  as 
may  have  been  necessary  to  produce  the  best  results  have  already 
been  applied  to  the  fibres  and  that  a  repetition  of  the  process 
cannot  help  but  have  a  tendency  to  unduly  shorten  the  fibres  and 
weaken  the  resultant  sheet. 


Treatment  of  Waste  Paper. 

The  papers  when  received  at  the  mill  have  to  be  sorted.  This 
should  be  done  in  a  light,  well  ventilated  room ;  light  being  neces¬ 
sary  if  the  papers  are  to  be  properly  sorted  and  all  dust  having 
to  be  carried  off  by  exhaust  fans  to  preserve  the  health  of  the 
workers.  The  paper  is  received  in  bales.  The  foreman  who  re¬ 
ceives  should  be  an  experienced  man  who  can  tell  at  a  glance  i 
the  bale  is  not  up  to  grade  so  it  can  be  rejected  before  it  is  dis¬ 
tributed  in  the  sorting  room.  The  sorters  are  usually  payed  at 
the  rate  of  so  much  per  hundred  pounds,  which  makes  for  effi¬ 
ciency,  and  with  practice  they  become  wonderfully  adept  at  this 
work.  If  the  grades  of  bales  received  contain  mixtures  of  a 
great  many  kinds  of  paper,  it  is  generally  necessary  to  pay  t  le 
sorters  by  the  day,  as  sorting  of  this  kind  of  stock  goes  very 

slowly.  .  r 

There  are  certain  standard  classifications  for  waste  paper 

stock  which  have  been  decided  on  by  the  biggest  firms  m  the  busi¬ 
ness  of  handling  this  material.  These  grades  are : 

No.  I  Book  and  Magazine  Stock.  Such  stock  must  be  tree 
from  ground  wood  paper,  parchment  paper,  leather  or  cloth  book 
covers,  magazine  covers  of  highly  colored  paper,  school  papei, 
paper  shavings,  photogravure  paper  and  books  with  burnt  edges. 
Certain  of  the  cheaper  magazines  will  not  be  accepted  as  No.  i 
stock,  such  as  “Popular.”  “All  Story,”  “Blue  Book,  etc.  Cheap 
novels,  telephone  directories,  mail  order  catalogs,  are  all  exclude 
from  this  class.  Thick  books,  like  Dun’s  Agency  books,_  must  be 
ripped  apart  into  sections  the  size  of  an  ordinary  magazine. 

Ledger  Stock.  Consists  of  high  class  writing  paper,  account 
books,  ledgers,  letters,  checks,  bonds,  insurance  policies,  leg 
documents,  etc.,  but  such  material  must  not  be  to.m  into  lit 
pieces.  Ledgers,  etc.,  must  be,  free  from  covers.  Postal  cards, 
school  books,  telegrams,  envelopes,  tissue  paper,  copying  paper, 


34  MODERN  PULP  AND  PAPER  MAKING 

manila,  highly  colored  paper,  bills  of  lading,  etc.,  will  not  be  ac¬ 
cepted  in  this  class. 

Mixed  Paper  Stock.  Consists  of  all  kinds  of  clean,  dry  paper 
from  office,  schools,  etc.  For  instance,  wrapping  paper,  card¬ 
board  boxes,  pamphlets,  telephone  books,  magazines  not  good 
enough  for  No.  i,  envelopes,  paper  torn  into  little  pieces,  crum¬ 
pled  newspapers,  etc.  Must  be  free  from  rubbish,  string,  leather, 
rags,  cloth  book  covers,  wire,  wood,  etc. 

Newspaper  Stock.  Clean,  folded  newspapers.  No  crumpled 
newspapers,  pamphlets,  etc. 

These  grades  are  further  subdivided  by  speaking  of  “Extra 
No.  I,”  etc. 

Prices  of  such  material  fluctuate  very  rapidly.  The  following 
table,  taken  from  “The  Paper  Industry”  for  June,  1920,  will 
indicate  how  this  material  is  quoted  on  and  roughly  what  is  the 
range  of  prices.  The  prices  are  in  cents  and  fractions  thereof  per 
pound. 


Hard  white  shavings,  No.  i . . 
Hard  white  shavings,  No.  2-3 

Soft  white  shavings . 

Colored  shavings . 

Heavy  book,  No.  i . 

Crumpled,  No.  i . 

Ledger  stock . 

Kraft,  No.  i . . 

Manilas,  No.  i . . 

White  blank  news . 

Overissue  news.  No.  i . 

Folded  news . 

Mill  wrappers . , 

Box  board  cuttings . 

Mixed  paper.  No  i . 

Common  paper . 


New  York  and  Chicago 

.  6  75-7 . 00 

.  5 ■ 50-6  25 

.  6 . 00-6 . 25 

•  •  •, .  2 . 50-2  75 

■  .  3  •  70-3  80 

.  300-3. 25 

.  3.8o-4'.oo 

.  4  00-4  25 

.  2 . 40-2 . 60 

.  4  25-4 ■ 50 

.  2 . 30-2 . 40 

.  2.00-2.10 

.  2.00-2.15 

.  I . 90-2 . 00 

.  I . 80-1 . 90 

.  I . lo-i .20 


The  old  process  of  working  up  waste  paper  consisted  in  pulp¬ 
ing  the^  paper  in  a  beating  engine,  after  which  the  stock  was 
placed  in  agitators  where  it  was  treated  with  caustic  soda  and 
finally  thoroughly  washed,  drained  and  furnished  to  the  beaters 
along  with  other  grades  of  stock  to  form  new  paper. 

Another  process  used  what  were  known  as  “bleach  tanks” 
although  such  equipment  was  never  used  for  what  could  properly 
be  called  bleaching.  These  tanks  were  large,  cylindrical,  steel 
plate  tanks,  provided  with  a  false  bottom  perforated  with  small 
holes.  In  the  center  is  a  vomit  pipe,  the  top  of  which  is  equipped 
with  a  baffle  plate,  to  spray  the  cooking  liquor  over  the  papers. 
The  papers  were  charged  into  the  tank  through  a  chute.  The 
liquor  consisted  of  caustic  soda  solution  about  2.1°  Be.  at  180°  F., 
that  being  the  temperature  at  which  the  cook  is  conducted.  The 
liquor  sprays  over  the  papers  in  an  intermittent  manner,  like  an 
ordinary  coffee  percolator.  With  this  process  it  is  stated  that 
1,750  pounds  of  caustic  soda  will  cook  6,000  pounds  of  waste 


MATERIALS  OF  PULP 


35 


paper  stock.  The  cook  requires  from  5  to  15  hours,  according  to 
conditions.  The  charging  of  the  tank  requires  from  1^2  to  2 
hours.  Longer  cooks  produce  better  results,  about  10  hours  being 
generally  very  satisfactory.  This  system  is  very  wasteful  of 
steam.  Covered  tanks  have  been  tried,  but  without  much  success. 
When  the  cook  is  completed  the  papers  are  removed  by  a  hoisting 
device,  operated  by  a  motor.  The  cooked  paper  is  forked  into  cars 
or  onto  a  conveyor.  This  work  requires  the  services  of  two  men 
for  two  hours  for  each  tank.  The  work  is  very  unhealthy  and 
disagreeable.  From  the  cooking  tank,  or  “bleach  tank”  as  it  is 
called,  the  papers  are  taken  to  washers,  which  may  be  either  chests 
with  agitators,  or  else  Hollanders  fitted  with  paddles  instead  of 
beater  rolls.  Sometimes  the  papers  go  first,  by  means  of  a  con¬ 
veyor  to  an  agitator,  in  which  they  are  pulped  sufficiently  fine  that 
they  can  be  pumped  with  a  fan  pump  to  the  washers.  The  pipe 
leading  to  the  washers  is  arranged  in  a  continuous  loop  so  that 
the  stock  will  always  be  in  circulation  and  no  clogging  will  result, 
the  feeders  to  the  washers  being  led  off  from  this  system  at  in¬ 
tervals. 

The  above  methods  are  wasteful  of  steam,  floor  space,  labor 
and  chemicals.  Moreover,  they  tend  to  disintegrate  the  stock 
much  more  than  is  necessary  for  stock  which  has  already  once 
been  through  the  process  of  paper  making.  They  are  gradually 
giving  way  to  more  modern,  efficient  and  economical  methods. 

Improvements  in  Treatment  of  Waste  Paper. 

Efforts  towards  improvements  in  the  treatment  of  waste  pa¬ 
pers  might  be  classified  into  three  general  divisions,  which  are, 
in  what  seems  to  us  to  be  the  order  of  their  importance : 

(1)  New  pulping  or  defibering  devices. 

(2)  Improved  washing  devices  designed  particularly  for  the 
treatment  of  pulp  made  from  waste  papers. 

(3)  New  chemicals  to  be  used  as  detergents  to  take  the  place 

of  caustic  or  soda  ash. 

During  the  last  few  years  several  machines  have  been  placed 
on  the  market  for  working  up  waste  papers,  for  which  the  in¬ 
ventors  make  various  claims.  Some  of  these  machines  are  de¬ 
signed  to  be  used  merely  to  give  the  papers  what  might  be  called 
preliminary  treatment.  Such  machines  break  up  the  books,  or 
large  bundles  of  paper  which  are  fed  into  them,  and  thus  prepare 
the  material  for  further  mechanical  refinement  and  complete  de- 

^^^Another  class  of  pulpers  consists  of  those  which,  while  de¬ 
signed  to  pulp  the  papers  so  that  they  are  ready  for  the  Jordan, 
or  possibly  for  the  paper  machine,  are  not  intended  to  do  more 
than  this.  In  other  words,  it  is  not  claimed  that  they  are  de¬ 
signed  to  liberate  the  ink  or  color,  both  of  which  remain  m  the 
pulp  and  are  not  capable  of  being  liberated  except  by  special 

treatment. 


36  MODERN  PULP  AND  PAPER  MAKING 

Still  another  type  is  on  the  market  for  which  the  inventors 
claim  not  only  pulping  and  de-fibering  qualities,  but  also  that  the 
action  of  the  machine  in  connection  with  the  use  of  a  suitable 
detergent,  will  liberate  the  ink  and  color  during,  and  coincident 
with,  the  process  of  de-fibering. 

Winestock  De-Fibering  and  De-Inking  Process. 

It  is  claimed  for  the  Winestock  De-fibering  and  De-inking  Ma¬ 
chine  and  Process  that,  in  addition  to  reducing  the  papers  to  a 
single  fibre  unit  without  appreciable  shortening  or  weakening  of 
the  fibres,  the  same  operation  also  liberates  the  ink  and  color  from 
the  fibres,  so  that  by  thorough  washing  the  fibres  are  restored  to 
the  color  of  the  original  pulp  before  coloring  matter  ever  was 
added.  It  is  also  claimed  that  this  result  can  be  obtained  whether 
the  papers  contain  ground  wood,  or  are  completely  free  from  it. 


CouTtesy:  Castle,  GotthcU  OvcTton,  New  York, 

Fig-  4- — Vertical  cross-section  of  Winestock  de-fibering  and  de-inking 
machine,  showing  circulation  of  stock. 


Most  black  printing  ink  consists  of  a  suspension  of  finely  di¬ 
vided  carbon  (lampblack,  carbon  black,  etc.)  in  some  oil  such  as 
pine  oil  or  linseed  oil.  After  the  type  has  transferred  the  ink  to 
the  paper,  some  of  the  oil  evaporates  and  the  remainder  is  ab¬ 
sorbed  by  the  paper,  holding  the  carbon  with  it.  As  carbon  is  not 
affected  by  any  bleaching  agents,  the  only  way  to  get  rid  of  the 
black  color  is  to  loosen  the  mixture  of  oil  and  carbon  from  the 
fibres  so  the  carbon  will  fall  off  during  the  washing.  Alkaline 


MATERIALS  OF  PULP 


37 


material,  such  as  soda  ash,  will  break  up  the  oil  and  free  the  car¬ 
bon  and  will  also  attack  the  rosin  with  which  the  paper  is  sized, 
which  also  helps  in  the  removal  of  the  ink. 

Consequently,  the  de-inking  and  de-fibering  of  waste  paper  is 
a  process  which  combines  chemical  and  mechanical  effects. 

The  principle  involved  in  the  Winestock  machine  is  novel, 
being  what  the  inventor  terms  “an  Inertia  Process.” 

The  de-fibering  action  is  performed  by  two  propellers  revolv¬ 
ing  rapidly — about  2,000  revolutions  per  minute — so  that  the 


Courtesy:  Castle,  Gottheil  &  Overton,  New  York. 

Fig.  5. — Winestock  de-fibering  and  de-inking  machine. 

water  is  unable  to  take  up  the  rotary  speed  of  the  propellers  and 
in  consequence  there  are  always  two  opposing  factors  the  speed 
of  the  propeller  and  the  inertia  of  the  liquid  stock. 

A  simple  illustration  of  this  principle  could  be  obtained  by 
floating  a  flat  sheet  of  paper  in  a  vat  of  water  and  then  striking 
the  floating  paper  a  sharp,  quick  blow  with  a  wooden  ^ 

switch  or  a  straight  piece  of  wire.  The  inertia  of  the  floating 
paper  could  not  be  overcome  quickly  enough  for  it  to  follow  ttie 
course  of  the  striking  object  and  the  result  would  be  a  cleavage— 
not  a  cutting — of  the  paper. 


38 


MODERN  PULP  AND  PAPER  MAKING 


This  describes  the  action  of  the  propeller  blades  on  the  paper 
floating  in  the  liquid.  This  action  is  facilitated  by  the  soda  ash 
or  other  detergent  used,  which  softens  the  size  in  the  paper  as  well 
as  the  binder  in  the  ink.  The  rapidly  moving  propeller  blades, 
while  disintegrating  the  paper  into  single  fibre  units  are,  at  the 
same  time,  knocking  the  loosened  ink  and  color  from  the  fibres 
themselves,  thus  accomplishing  the  de-fibering  and  de-inking  at 
the  same  time,  as  before  mentioned. 

A  novel  and  effective  method  of  circulation  is  provided, 
whereby  the  pulp,  after  passing  through  the  propeller  tube,  is  dis¬ 
charged  tangentially  into  a  large  circulating  tank,  entering  the 
tank  at  the  bottom  and  working  to  the  top  with  a  spiral  motion. 
At  the  top  it  cascades  over  into  an  upright  cylindrical  tank  which, 
in  turn,  leads  the  stock  again  to  the  propeller  tube. 

The  circulation  is  very  active  and  continues  until  the  paper  is 
thoroughly  de-fibered. 

Softening  tanks  should  always  be  used  in  connection  with  this 
machine,  as  they  enable  the  machine  to  complete  its  work  in  ap¬ 
preciably  shorter  time. 

A  type  of  softening  tank  that  has  been  found  to  work  very 
satisfactorily  consists  of  an  upright  chest  with  a  perpendicular 
shaft  running  through  the  center.  In  place  of  the  ordinary  agita¬ 
tors  two  sets  of  fans  are  bolted  to  the  shaft  with  the  blades  so 
pitched  that  the  mass  is  thrown  upwards.  One  set  of  fans  (there 
are  two  blades  to  each  set)  operates  at  the  bottom  of  the  tank 
with  just  room  enough  for  clearance,  and  the  second  set  is  located 
midway  between  the  top  and  the  bottom.  The  speed  of  the  shaft 
is  25  revolutions  per  minute. 

In  some  cases  “breaking  up”  engines  are  being  used  with  ex¬ 
cellent  results  and  this  method  is  especially  good  where  solid  stock 
is  used  such  as  solid  ledgers,  telephone  books,  etc.,  which  may  be 
fed  into  such  a  machine  without  first  tearing  the  books  apart. 

Books  and  magazines  to  be  manufactured  into  white  paper 
require  from  35  to  40  minutes  of  treatment,  while  hard-sized  pa¬ 
per  containing  writing,  printing,  engraving,  etc.,  requires  a  some¬ 
what  lengthier  treatment  to  obtain  most  satisfactory  results. 

The  machine  holds  from  700  pounds  to  900  pounds  of  dry 
papers  at  a  charge,  and  the  average  production  ranges  from  12 
to  15  to’.s  per  24  hours.  From  the  Winestock  machine  the 
papers  go  to  a  washer  and  then  follow  the  usual  process  of 
manufacture. 

Owing  to  the  fact  that  the  paper  is  completely  de-fibered  and 
the  color  and  ink  thrown  into  a  solution  or  emulsion  in  the  water, 
the  pulp  washes  more  quickly  than  stock  treated  by  rotary  or 
open  bleach.  The  mass  as  it  comes  from  the  Winestock  machine 
has  an  entirely  different  and  more  satisfactory  appearance  than 
the  product  of  the  rotary  or  open  bleach. 

Book  papers,  for  example,  instead  of  being  brown  or  nearly 
black,  give  a  grayish  colored  pulp.  If  this  pulp  be  thoroughly 


MATERIALS  OF  PULP 


39 


washed  on  a  small  hand  screen,  the  individual  fibres  will  be  found 
to  be  as  white  as  the  original  paper  from  which  the  pulp  was 
made.  Under  actual  mill  conditions  the  ordinary  washing  engine 
does  not  give  the  stock  the  proportionate  amount  of  flushing  and 
agitation  that  is  obtainable  by  hand  washing,  and  it  may  he  found 
necessary  to  use  a  small  amount  of  bleach  to  tone  up  the  color. 
This  is,  however,  more  a  limitation  of  the  washing  engine  than 
of  the  de-fihering  machine  itself,  for  the  hand  washing  shows  con¬ 
clusively  that  the  fibres  are  in  no  way  discolored.  It  is  asserted 
that  this  result  is  obtained  because  the  mechanical  action  of  the 
machine,  and  the  principle  involved,  enables  it  to  accomplish  its 
work  in  the  shortest  possible  time,  with  a  minimum  amount  of 
chemicals,  and  at  a  low  temperature — from  i6o  degrees  to  190 
degrees  Fahrenheit. 

It  seems  only  reasonable  to  assume  that,  inasmuch  as  the  ink 
and  color  are  actually  knocked  off  the  fibres  and  into  the  water, 
that  the  result  would  be  a  pulp  that  would  require  less  washing 
than  would  be  the  case  if  the  ink  and  color  were  cooked  into  the 
fibre  during  a  treatment  lasting  several  hours,  or  kneaded  in 
by  the  action  of  an  ordinary  pulper. 

In  addition,  the  violent  scrubbing  to  which  the  fibres  are  sub¬ 
jected  in  the  soapy,  alkaline  liquor  is  a  big  factor  in  producing 
bright,  clean  pulp. 


/ 


III.  Varieties  of  Paper. 

The  art  of  paper  making  having  been  known  for  over  T,8oo 
years,  naturally  paper  has  come  to  be  used  for  a  great  variety  of 
purposes,  and  as  the  uses  for  paper  have  broadened,  there  has 
come  to  be  a  corresponding  specialization  in  the  kinds  of  paper 
manufactured  for  these  various  uses. 

The  following  tabulation  of  the  Pulp  and  Paper  Industry  of 
the  United  States  was  made  by  S.  L.  Wilson,  Chief  of  the  Manu¬ 
facturing  Section  of  the  Pulp  and  Paper  Division  of  the  War 
Industries  Board : 

There  were  (in  1918)  821  pulp  and  paper  mills  in  the  United 
States  producing  annually  about  5,658,000  tons  of  paper  and 
boards.  Classified  according  to  general  grades,  these  are  divided 
as  follows : 


Tons 

Production  Approximate 

Y  early 

Daily 

Value 

Newsprint . 

.  .  .  .  1,360,000 

4,200 

$136,000,000 

Book^ . .• 

....  780,000 

2,600 

125,000,000 

Boards . 

-  1,950,000 

6,500 

1 56,000,00*0 

Wrappings . 

-  705  >000 

2,350 

89,000,000 

Fine  Writings . 

.  . .  .  405,000 

1,360 

142,000,000 

Tissue . 

.  .  .  .  132,000 

440 

27,000,000 

Building  Felts . 

.  .  .  .  249,000 

830 

50,000,000 

Miscellaneous . 

.  .  .  .  177,000 

590 

55,000,000 

Imported  from  Canada — 

(Newsprint) . . 

....  560,000 

1,840 

6,218,000 

20,700 

Exported — 

(6  months  actual) . 

.  .  .  .  147,875 

Y  early — 

(6  months  estimated) . 

.  .  .  .  147,875 

Total  Domestic  Consumption . 

- 5,922,250 

1  Book  paper  totals  in  government  statistics  include  practically  everything  used  for  printing 
purposes  except  the  newsprint.  The  periodicals  would  use  the  larger  proportion  of  this  780,000 
tons,  and  circulars,  bulletins,  catalogs,  government  reports  and  job  printing  of  every  descrip¬ 
tion  the  balance.  Books  in  bound  form  probably  do  not  use  over  5  or  6  per  cent  of  this  total 
of  book  paper. 


Writing  and  Book  Paper. 

The  different  kinds  of  paper  are  made  by  using  different 
kinds  of  raw  stock  and  varying  the  processes  to  which  this  raw 
stock  is  submitted. 

One  of  the  oldest  and  most  important  branches  of  the  paper 
industry  is  that  involving  the  manufacture  of  writing,  book  and 

40 


VARIETIES  OF  PAPER 


41 


high  grade  printing  papers.  The  properties  of  papers  of  this 
type  are  such  as  to  exhibit  the  following  main  characteristics : 

(1)  An  even,  uniformly  closed  sheet. 

(2)  A  soft,  strong,  pliable  sheet. 

(3)  A  high  finish  with  an  even  bulk. 

To  obtain  the  above  characteristics,  specially  prepared  pulp 
must  be  used.  The  ideal  fibre  is  one  which  retains  its  original 
length,  strength  and  elasticity  as  completely  as  possible  after  hav¬ 
ing  been  prepared  into  “half  stuff,”  i.  e.,  after  the  cooking  and 
bleaching  processes  are  finished.  The  pulp  must  be  an  easy 
bleaching  stock,  or  otherwise  a  hard,  brittle  fibre  will  be  produced 
with  very  poor  felting  qualities  and  the  resulting  sheet  will  be 
unsatisfactory  no  matter  what  precautions  are  taken  later  on  in 
the  beater  room  and  machine  room. 

Book  paper  is  chiefly  made  from  rag  (cotton  and  linen)  pulp, 
sulphite  and  soda  wood  pulp  and,  in  the  cheaper  grades,  some 
ground  wood,  all  of  which  are  bleached.  Esparto  pulp  has  also 
found  a  wide  application  in  the  manufacture  of  medium  quality 
book  papers  and  writings. 

In  addition  to  the  various  combinations  of  stock  that  may  be 
used  in  the  making  of  book  paper,  loading  materials  must  be 
added  to  the  extent  of  from  10  to  15  per  cent,  so  as  to  make  the 
paper  more  absorbent  and  opaque,  and  to  enable  a  clear  print  to 
be  made.  Such  materials  also  lessen  to  a  large  extent  the  friction 
when  the  paper  and  type  come  in  contact  during  the  printing.  In 
selecting  the  loading  materials  a  number  of  considerations  have 
to  be  kept  constantly  in  mind. 

First:  The  chemical  nature  of  the  substance  itself  must  be 
examined.  Any  substance  containing  free  acid  or  chlorine  com¬ 
pounds  cannot  be  used. 

Second:  A  finely  graded  material,  of  uniform  consistency, 
free  from  sand  and  grit  is  necessary. 

Third:  The  material  must  be  of  such  a  color  that  it  will  not 
interfere  with  the  shade  of  the  finished  paper. 

Kaolin,  or  clay,’^  is  the  chief  substance  used  for  loading  book 
paper.  It  fills  up  the  pores  of  the  paper,  giving  a  sheet  of  closer 
texture  that  will  take  up  ink  rapidly  and  it  enables  a  high  finish 
being  obtained  in  the  calenders."  Papers  requiring  a  higher  finish 
than  is  possible  to  achieve  with  the  machine  calenders  are  gen¬ 
erally  finished  in  supercalenders,^  where  the  high  pressure  and 
the  contact  between  the  upper  metal  and  the  bottom  paper-covered 
rolls  has  the  effect  of  imparting  a  velvety  surface  necessary  for 
illustrated  work  where  halftones  are  used  and  for  the  finer  sorts 


of  printing.  _  .  , 

The  highly  surfaced  papers  on  which  some  books  are  printed, 
especially  when  fine  half-tones  have  to  be  brought  out,  are  known 
as  coated  papers.  The  preparation  of  such  papers  is  a  line  of  in- 


1  See  Chapter  XII  for  full  discussion  of  use  of  clay. 

=  See  Chapter  XIII  for  construction  and  operation  of  calenders. 

See  Chapter  XIV  for  construction  and  operation  of  supercalenders. 


42 


MODERN  PULP  AND  PAPER  MAKING 


dustry  really  separate  from  the  manufacture  of  paper,  but  a  few 
words  of  description  may  not  be  amiss  at  this  point. 

The  solution  with  which  the  paper  is  coated  is  usually  com¬ 
posed  of  clay  or  talc  suspended  in  a  sort  of  size  made  of  casein, 
starch  or  some  other  adhesive.  Blanc  fixe  (barium  sulphate)  and 
various  special  white  substances  such  as  “paper-makers’  white,” 
“satin  white,”  etc.,  are  sometimes  used  instead  of  clay. 

The  rolls  of  paper  received  from  the  paper  mill  are  unwound 
and  pass  over  rollers  where  one  side  comes  in  contact  with  a  brush 
device  which  applies  the  coating  liquid.  There  is  a  system  of 
other  brushes  to  distribute  evenly  the  coating,  after  which  the 
coated  sheet  is  suspended  over  a  series  of  wooden  bars  borne  by 
traveling  chains  at  each  end  so  that  it  hangs  in  a  series  of  festoons 


Fig.  6. — Interior  of  coating  mill  showing  festoons. 

while  drying.  This  equipment  is  of  sufficient  size  that  several 
hundred  feet  of  paper  are  exposed  to  the  air  at  one  time,  with  the 
result  that  by  the  time  the  end  of  the  system  is  reached  the  coated 
side  is  sufficiently  dry  that  the  paper  may  be  rolled  up.  Some¬ 
times  it  is  run  back  through  the  machine  to  coat  the  reverse  side. 
Other  machines  have  been  devised  which  coat  both  sides  in  one 
operation.  After  the  paper  has  been  coated  and  dried  it  is  run 
through  various  calendering  machines  to  produce  exactly  the 
finish  desired  and  is  then  rolled  or  cut  into  sheets  for  shipment. 


VARIETIES  OF  PAPER 


43 


Grades  of  Book  Paper. 

According  to  the  U.  S.  Government  Report  on  the  Book  Paper 
Industry  ^  Book  Paper  is  a  general  term  designating  roughly  all 
of  the  grades  of  printing  paper  except  newsprint.  The  chief  dis¬ 
tinction  between  book  paper  and  newsprint  is  that  the  former  is 
made  chiefly  of  chemical  pulp  while  the  latter  consists  mainly  of 
mechanical  pulp.  Standard  newsprint  consists  usually  of  about 
8o  per  cent  mechanical  pulp  and  20  per  cent  sulphite.  Between 
standard  newsprint  and  book  paper  there  are  various  intermediate 
grades  containing  more  or  less  ground  wood  and  known  as  half¬ 
tone  news,  special  news,  novel  news,  catalog  news,  etc. 

The  principal  grades  of  book  paper  are  machine  finish  (M. 
F.),  sized  and  supercalendered  (S.  &  S.  C.),  coated,  and  cover. 
The  difference  in  the  first  three  grades  lies  mainly  in  the  finish 
given  the  paper.  This  book,  for  instance,  is  printed  on  sized  and 
supercalendered  paper.  Cover  paper  is  a  strong,  heavy  grade, 
and  is  usually  coated.  It  is  used  mainly  for  the  covers  of  maga¬ 
zines,  catalogs,  etc.  Within  each  of  these  grades  there  are 
numerous  variations  in  the  specifications  for  size,  weight,  color, 
etc. 

Machine  finish  book  paper  goes  through  practically  the  same 
manufacturing  process  as  newsprint.  It  receives  no  finish  but  that 
given  by  the  calender  rolls  at  the  dry  end  of  the  paper  machine. 
Some  variation  in  finish  is  possible,  however.  Such  variations 
are  laid,  wove,  English  finish,  high  bulk,  eggshell,  etc.  The  term 
“laid”  denotes  certain  markings  in  the  sheet  consisting  of  promi¬ 
nent  vertical  watermark  lines  some  distance  apart  and  somewhat 
smaller  horizontal  lines  much  closer  together.  “Wove”  is  ordi¬ 
nary  machine  finish  with  fine,  almost  imperceptible,  equidistant 
markings.  “English  finish”  denotes  a  dull  surface  with  a  velvety 
feel.  “High  hulk”  is  a  thick,  blotter-like  paper,  soft  and  not  much 
compressed.  “Eggshell”  is  a  rough  finish  in  imitation  of  the 
texture  of  an  egg  shell.  These  different  finishes  are  made  by 
watermarking,  by  rollers  of  different  design  which  press  on  the 
paper  while  it  is  still  moist,  and  by  variations  in  the  pressure 
applied  at  the  calenders.  Machine  finish  paper  is  used  largely  by 
publishers  of  books  and  for  trade  catalogs,  etc. 

Sized  and  supercalendered  paper  is  machine  finished  paper 
which  has  undergone  an  additional  process  of  sizing  and  calender¬ 
ing  to  give  it  a  high  finish.  This  is  the  paper  most  used  for  the 
higher  grade  of  illustrated  magazines  and  also  for  trade  catalogs, 
advertising  literature  and  many  books. 

The  uses  of  book  paper  are  not  confined  to  the  printing  of 
books,  magazines  and  catalogs,  etc.  It  is  used  for  cheap  writing 
pads  and  school  exercise  books,  for  wrappings  for  soap  and 
pharmaceutical  products,  and  for  lining  and  covering  paper  boxes. 
Very  fine  papers  for  money,  stock  certificates,  etc.,  are  made  in 
mills  where  the  most  extreme  precautions  as  to  boiling,  washing, 

'  Senate  Document  No.  79,  igi7' 


44  MODERN  PULP  AND  PAPER  MAKING 

bleaching  and  beating  are  exercised.  Quantity  production  is  no 
object,  small  size  ecjuipment  is  used,  and  time  and  attention  lav 
ished  on  each  process. 

Writing  Paper. 

The  manufacture  of  writing  paper  calls  for  about  the  same 
requirements  as  book  paper.  However,  in  writing  papei  special 
watermarks,  engravings  and  finishes  are  more  generally  applied. 
The  one  usually  called  for  is  linen  finish. 

Linen  Einish:  This  effect  is  made  only  on  high  class  work. 
The  paper  is  taken  from  the  machine  in  a  moist  condition  in  the 
form  of  sheets.  It  is  then  hung  up  on  poles  to  dry  in  a  drying 
loft,  where  it  is  usually  kept  for  about  24  to  30  hours.  ^  When 
taken  from  the  loft  the  paper  must  still  be  a  trifle  damp  in  order 
that  the  impression  of  the  linen  may  be  mpre  easily  taken. The 
paper  is  now  ready  to  receive  the  linen  finish,  which  operation  is 
conducted  on  plate  rolls  operated  under  great  pressure.  A  sheet 
of  the  best  grade  of  linen  is  placed  upon  a  sheet  of  heavy  tin. 
Then  a  sheet  of  paper  is  placed  on  the  linen,  followed  by  another 
sheet  of  linen,  and  so  on  until  a  pack  of  sheets  of  tin,  linen  and 
paper  is  made  about  4  inches  thick.  This  pack  is  then  run 
through  the  plate  rolls  and  the  paper  receives  the  imprint  of  the 
linen. 

Wrapping  Papers. 

W^rapping  papers  are  made  from  various  combinations  of 
Kraft,  sulphite,  ground  wood  and  waste  paper.  Frequently  sul¬ 
phite  screening  stock^  is  used  in  conjunction  with  the  above  ma¬ 
terials.  Jute  and  various  combinations  of  jute  and  inferior  stocks 
have  had  a  wide  application  in  the  past  but  such  materials  are  now 
being  supplanted  by  Kraft  wrappers.  ^ 

Kraft  zvrapping,  although  a  variety  of  paper  .still  Jn  its  in¬ 
fancy,  is  leading  all  the  other  combinations  for  wrapping  heavy 
bundles.  As  a  result  of  the  great  strength  of  its  fibres  and  their 
flexibility  and  compactness,  a  wonderful  sheet  can  be  made  for 
this  kind  of  service. 

Depending  upon  the  specific  service  that  is  to  be  required  of  a 
wrapping  paper,  there  are  many  modifications  that  can  be  made 
in  the  furnish  used  to  make  up  a  desirable  paper.  It  is  not  de¬ 
sirable  to  incorporate  mechanical  wood  pulp  in  a  wrapper  of 
heavy  weight  that  is  going  to  encounter  hard  usage.  ^  As  a  result 
of  the  shortness  of  the  fibres  in  such  paper,  and  their  weakness, 
it  is  devoid  of  all  flexibility  and  strength.  However,  such  com¬ 
binations  (colored  up  to  resemble  the  true  Kraft  color)  are  often 

sold  as  Kraft  wrappers.  .  . 

A  variety  of  pulp  that  at  one  time  made  a  very  good  imitation 
of  Kraft  is  the  so-called  “brozm  zvrapper”  This  was  made  from 
pulp  obtained  by  steaming  the  wood  at  a  high  temperature,  thus 

For  origin  of  sulohite  screenings  see  Chapter  VI. 


VARIETIES  OF  PAPER 


¥ 


45 


softening  the  fibre  to  a  certain  extent,  and  then  grinding  by  the 
regular  mechanical  process.  The  wood  is  thus  easily  ground  and 
yields,  a  pulp  containing  long  fibres,  which,  in  their  physical  prop¬ 
erties,  closely  resemble  those  of  pure  wood  cellulose.  However, 
all  the  original  constituents  of  the  wood  besides  cellulose  are  pres¬ 
ent,  chiefly  lignins,  and  these  are  almost  unchanged,  as  in  the  me¬ 
chanical  pulp.  Such  paper  has  been  almost  entirely  replaced  by 
Kraft,  and  mixtures  of  Kraft  and  sulphite  and  other  combina¬ 
tions. 

Another  well  known  form  of  wrapping  paper  is  the  so-called 
“ButchersP  The  prime  requisite  for  such  papers  is  sizing  qual¬ 
ity.  They  must  be  so  sized  as  to  stand  what  is  known  as  the 
“blood  test.”  This  is  a  test  devised  to  determine  the  resistance 
of  the  paper  to  blood,  as  such  papers  are  intended  for  the  use  of 
butchers  in  wrapping  meats.  These  papers  are  ordinarily  made 
by  using  6o  per  cent  sulphite  and  40  per  cent  ground  wood  in  the 
unbleached  state.  Nearly  all  these  grades  are  given  a  slight 
water  finish  which  tends  to  raise  the  sizing  of  the  sheet.  The 
standard  weight  on  such  sheets  has  been  taken  at  40  pounds,  24X 
36  inches,  480  sheets  to  the  ream.  There  are,  however,  some 
manufacturers  making  weights  both  above  and  under  the  above 
weight. 

Manila  papers  have  also  obtained  considerable  importance  in 
the  wrapping  paper  field.  Such  papers  were  originally  made 
from  pulp  prepared  from  Manila  rope,’^  but  the  term  is  now  ap¬ 
plied  to  papers  made  from  sulphite  and  ground  wood  and  colored 
to  imitate  the  characteristic  Manila  shade.  One  of  the  essential 
features  of  a  good  Manila  sheet  is  cleanliness.  In  order  to  obtain 
this  quality  many  manufacturers  apply  special  screening  devices 
so  as  to  get  good  stock  quite  free  from  dirt  specks  and  uncooked 
shieves.  A  careful  examination  of  Manila  sheets  made  through¬ 
out  the  country  would  lead  one  to  the  opinion  that  there  are  many 
different  ideas  as  to  what  kind  of  a  finish  is  suitable  for  a  first 
class  Manila  sheet.  It  is  generally  conceded,  however,  that  a 
high  steam  finish  is  mainly  to  be  desired.  This  gives  a  soft,  flexi¬ 
ble  sheet,  which,  when  crumpled  up,  will  give  one  the  impression 
of  a  silky  feel. 

Cutlery  papers  are  required  to  show  complete  freedom  from 
chemical  residues  which  would  tarnish  the  polished  metal  goods 
which  are  wrapped  in  them.  The  residues  most  likely  to  be 
present  are  sulphur  compounds  and  these  may  easily  be  tested  for 
by  warming  the  paper  with  dilute  acid  in  a  test  tube,  holding  a 
slip  of  filter  paper  dipped  in  lead  acetate  across  the  mouth  of  the 
test  tube  and  noting  whether  or  not  the  paper  saturated  with  the 
lead  acetate  solution  is  blackened.  If  it  is  blackened  it  indicates 
the  presence  of  sulphur  in  the  paper  being  tested.  Acidity  in 
cutlery  wrapping  papers  is  also  highly  undesirable. 

The  papers  used  for  packing  small  goods,  such  as  silverware 


*  See  Chapter  II. 


MODERN  PULP  AND  PAPER  MAKING 


46 

and  other  delicate  articles,  are  generally  tissues,  the  better  quali¬ 
ties  of  which  are  made  from  sulphite  and  rag  stock.  Such  papers 
must  also  be  entirely  free  from  sulphur  and  acidity  which  would 
have  a  damaging  effect  on  silver  and  other  fine  metal  articles. 

Tissue  and  Cigarette  Papers. 

These  papers  constitute  a  distinct  class  on  account  of  their 
extreme  thinness.  They  cannot  well  be  made  on  ordinary  paper 
machines  as  the  web  of  paper  has  not  the  necessary  strength  to 
carry  across  from  one  part  of  the  machine  to  another,  and  must, 
at  all  times,  be  supported  on  a  felt.  Also,  being  very  thin,  they 
do  not  need  as  much  pressing  and  drying  as  ordinary  paper, 
one  set  of  press  rolls  usually  being  sufficient.  The  Harper 
Fourdrinier  machine  is  excellent  for  such  papers.  This  machine 
will  be  described  in  detail  in  the  chapter  on  the  machine  room. 
The  drying  part  of  the  machine  is  frequently  equipped  with  a 
Yankee  dryer,  which  will  also  be  described  in  the  chapter  on  the 
machine  room.  Special  devices  are  used  in  many  mills  for 
imparting  crepe  finish  to  tissue  papers.  These  are  like  calenders 
with  corrugated  rolls.  The  extended  use  of  paper  towels  has 
led  to  the  development  of  special  papers  resembling  both  tissue 
and  blotting  in  qualities. 

Cigarette  Paper:  Cigarette  paper  is  best  made  on  a  Harper 
Fourdrinier  or  a  Flying  Dutchman  or  Yankee  machine  (known 
in  England  as  an  M.  G.  machine).  Only  recently  the  best 
cigarette  paper  has  been  made  chiefly  in  France,  Germany,  Italy 
and  Austria,  but  now  very  satisfactory  grades  are  being  made 
in  America. 

A  good  cigarette  paper  should  be  absolutely  neutral  in  flavor 
and  aroma  while  the  cigarette  is  burning.  As  very  few  vegetable 
fibres  possess  these  properties,  the  selection  of  material  is  most 
important  in  making  this  kind  of  paper.  Pure  flax,  or  linen 
fibre,  hemp  fibre  and  ramie,  are  usually  used.  Rice  straw  was 
formerly  extensively  used  for  making  cigarette  paper  but  this 
stock  does  not  possess  strength  to  satisfy  the  requirements  of 
modern  cigarette  making  machinery.  Chemical  wood  pulp  is 
only  used  for  the  cheapest  grades  of  cigarette  papers.  It  is 
deficient  in  tensile  strength  unless  it  is  too  thick.  Straw  papers 
usually  contain  silicic  acid  which  is  undesirable  in  cigarette 
papers  as  it  confers  disagreeable  burning  properties  to  the  paper. 
Excessive  use  of  cotton  fibre  gives  the  lamp  wick  odor  found  in 
some  of  the  cheaper  grades  of  cigarette  paper. 

According  to  Stroud  Jordan  the  analysis  of  samples  from 
reels  of  paper  actually  running  on  cigarette  machines  revealed 
that  these  papers  were  made  up  chiefly  of  linen  fibre  slightly 
sized  with  starch  or  dextrine  and  filled  with  magnesium  or  calcium 
carbonate.  The  filler  in  three  of  the  samples  (Austrian)  aver¬ 
aged  24.05  per  cent  and  in  two  other  samples  (French)  averaged 
9.13  per  cent.  _ 


VARIETIES  OE  PAPER 


47 


A  good  cigarette  paper  should  weigh  from  lo  to  20  grams 
per  square  meter.  With  the  former  weight  the  paper  should  be 
0.014  mm.  thick  and  a  20  gram  paper  should  be  0.037  ^nm.  thick. 

Porosity  is  necessary  to  admit  air  for  the  proper  combustion 
of  the  paper.  Cigarette  papers  are  being  made  somewhat  thicker 
today  than  formerly  on  account  of  the  necessity  for  strength 
in  paper  to  be  used  on  cigarette  machines  and  the  manufacture 
of  paper  of  the  proper  thickness  and  strength  with  sufficient 
porosity  is  quite  a  problem.  Opaqueness  is  also  necessary  in 
order  to  give  a  good  appearance  to  the  finished  cigarette.  If  the 
paper  is  not  sufficiently  opaque,  the  tobacco  will  show  through  the 
paper  giving  the  cigarette  a  grayish  or  mottled  appearance  when 
packed  which  is  undesirable  from  the  cigarette  manufacturers’ 
point  of  view.  Securing  the  necessary  opaqueness  without  mak¬ 
ing  the  paper  too  thick  is  one  of  the  nice  points  in  the  manu¬ 
facture  of  this  variety  of  paper. 

The  boiling  of  the  stock  is  very  important.  The  slightest 
variation  in  the  cooking  process,  whether  in  time,  temperature, 
pressure  or  chemicals  employed,  may  disastrously  atfect  the 
character  of  the  material,  interfering  with  beating  to  the  proper 
consistency  and  causing  a  great  deal  of  trouble  through  tearing 
on  the  machine.  Cigarette  paper  should  be  beaten  with  very  dull 
knives.  After  beating,  it  is  bleached,  very  thoroughly  washed 
and  then  drained  and  stored  for  several  months  to  ripen.  This 
ripening  process  is  necessary  to  give  the  paper  the  desired 
opaqueness  and  soft,  silklike  feel. 

The  operation  of  the  machine  in  manufacturing  cigarette 
paper  is  a  very  delicate  problem.  With  no  paper  is  exactness  in 
regulating  the  flow  of  stuff  on  to  the  wire  so  necessary.  The 
machine  must  be  very  carefully  cared  for  as  very  fine  wires 
are  used  which  easily  become  filled  up  with  slime  and  dirt.  Such 
paper  is  usually  made  at  a  speed  of  about  130  feet  per  minute 
on  a  machine  giving  a  web  58  inches  wide. 

In  making  very  thin  papers  on  fast  running  machines,  there 
is  always  a  danger  of  the  paper  sticking  to  the  upper  press  roll. 
In  order  to  avoid  this  trouble,  most  careful  attention  must  be 
given  to  the  condition  of  the  stock.  If  this  is  not  right,  that  is, 
if  the  stock  has  not  been  cooked  and  beaten  in  just  the  proper 
manner,  no  amount  of  adjustment  of  the  machine  will  give 

satisfactory  results.  _  ^  1  j  •  ^ 

In  making  very  thin  papers  in  which  ground  wood  is  used, 
careful  attention  must  be  paid  to  the  selection  of  the  ground 
wood,  that  prepared  by  the  hot  grinding  process  being  most 
suitable.  If  sulphite  pulp  is  used,  it  must  be  entirely  free  from 
pitch  and  sticky  resinous  matter  and  must  possess  a  sott  but 
sound  fibre.  If  the  original  quality  of  the  pulp  is  not  right,  it 
cannot  be  made  right  by  any  treatment  in  the  beater  or  on  tlie 
machine.  If  a  sulphite  pulp  has  been  cooked  too  quickly,  or 
with  an  unsuitable  acid,  or  an  unsuitable  pressure,  or  if  a  median- 


48  MODERN  PULP  AND  PAPER  MAKING 

ical  pulp  has  been  ground  from  old  wood,  or  with  the  wrong  kind 
of  stones,  the  pulp  will  never  do  for  tissue  or  any  other  kind  of 
unusually  thin  paper. 

Bag  Paper. 

The  required  qualities  in  bag  paper  are:  tensile  strength,  pli¬ 
ability,  tearing  and  bending  qualities,  a  certain  resistance  to 
moisture,  a  smooth  printing  surface  and,  in  some  lines,  a  con¬ 
siderable  bulkiness  (e.  g.  in  sugar  bags,  sacks,  etc.). 

The  materials  and  the  method  of  manufacture  must  both  be 
chosen  with  a  specific  view  to  the  fact  that  the  paper  is  to  be 
used  for  bag  purposes.  Paper  does  not  become  bag  paper 
merely  by  virtue  of  having  been  run  through  a  bag  machine 
and  made  into  a  bag.  Conversely,  there  are  several  uses  for  bag 
paper  other  than  the  manufacture  of  bags. 

Bags  serve  not  only  as  containers,  but  also  as  carriers,^  and 
the  stock  must  be  sufficiently  strong  and  pliable  to  permit  of 
the  bag  being  twisted,  folded  and  gathered  into  improvised 
“handles.”  This  feature  of  the  use  of  paper  bags  submits  the 
bag  to  a  strain  unique  in  paper  usage.  The  strain  applied  to  a 
paper  bag  in  carrying  home,  say,  a  few  pounds  of  nails,  is  only 
under  other  circumstances  applied  to  materials  much  stronger 
than  paper. 

Good  bag  paper  mus’t  be  soft  and  pliable ;  must  not  be  harsh 
or  brittle ;  and  must  have  good  folding  qualities  to  survive  un¬ 
impaired  the  sharp  creasing  it  receives  in  use.  Moreover,  since 
not  all  the  strain  the  paper  bag  receives  is  tensile,  one  of  the 
strains  being  the  potential  rupture  of  the  sheet  due  tO'  pressure 
of  merchandise  (individual  pieces  of  merchandise  in  many  cases, 
such  as  apples,  vegetables  and  the  like)  we  see  that  the  fibres 
must  not  run  too  definitely  in  any  one  direction,  i.  e.,  they  must 
not  form  a  distinct  “grain”  running  lengthwise  of  the  bag.  That 
would  invite  easy  splitting  of  the  sheet.  Consequently,  it  is 
necessary  ,  to  exert  every  effort  to  make  a  sheet  that  will  have 
equal  tearing-strength  in  all  directions.  From  the  very  begin¬ 
ning  of  the  art  of  making  paper,  this  has  been  regarded  as  very 
difficult.  In  addition  to  eliminating  a  definite  “grain”  the  sheet 
must  be  properly  “closed,”  which  will  be  more  completely  under¬ 
stood  after  the  chapter  on  the  paper  machine  has  been  studied. 
If  the  sheet  is  exclusively  formed  of  long  fibres,  it  will  be  all 
the  better  if  it  is  properly  closed  and  the  fibres  properly  criss¬ 
crossed,  on  the  paper  machine,  avoiding  variation  of  strength  in 
one  square  inch  of  the  sheet  compared  to  the  next  inch.  Hence 
the  fibres  must  always  be  long  enough  so  that  the  edge  of  the 
sheet  will  present  a  ragged  and  truly  fibrous  appearance  when 
torn  in  any  direction.  A  sheet  of  bag  paper  will  frequently, 
against  the  light,  appear  to  be  relatively  “wild”  (that  is  when 
compared  with  varieties  of  paper  other  than  bag  and  wrap- 


VARIETIES  OE  PAPER 


49 


ping)  and  yet  with  splendid  bag  qualities  in  general,  and  without 
appreciable  variation  of  strength  inch  by  inch.  Further,  just 
enough  size  and  alum  must  be  used.  There  must  be  enough  size 
to  enable  the  bag  to  withstand  quite  a  little  moisture  in  the  course 
of  its  use,  and  also  to  prevent  too  great  penetration  of  moist 
materials.  Only  enough  alum  must  be  used  to  precipitate  the 
sizing  material  otherwise  the  sheet  will  be  made  too  brittle. 

Bag  papers  for  the  most  severe  service  can  best  be  made 
of  Kraft  pulp,  and  with  lessening  severity  of  service,  larger 
percentages  of  sulphite  can  be  intermixed,  until  a  point  is  reached 
where  the  bag  is  intended  for  uses  where  very  little  s^ess  is 
ever  applied  to  its  surface,  when  combinations  of  sulphite  and 
ground  wood  will  suffice.  The  above  remarks  refer  to  the 
regular  grades  of  bag  paper.  There  are  many  specialties  on  the 
market  which  call  for  specially  prepared  paper  consisting  of 
jute,  bleached  soda  pulp,  bleached  sulphite  pulp,  heavily  loaded 
papers,  parchment,  etc. 


Parchment  Papers. 

Real  parchment  paper  consists  of  unsized  rag,  or  other  high 
grade  stock  which  has  been  treated  in  a  bath  of  dilute  sul¬ 
phuric  acid.'  After  treatment  with  the  acid  the  paper  is  washed 
with  water  and  then  with  dilute  alkali  to  neutralize  any  trace 
of  acid  remaining  and  finally  with  pure  water  again  to  remove 
the  alkali.  This  is  done  on  a  special  machine  where  the  web  oi 
paper  passes  into  a  vat  for  treatment  with  the  acid  and  then 
between  rolls  to  remove  surplus  liquid  after  which  it  passes 
into  the  vats  containing  the  dilute  alkali  and  water.  This  treat¬ 
ment  increases  the  tensile  strength  of  the  paper  to  a  remarkable 
degree  and  yields  it  many  of  the  properties  of  animal  parch¬ 
ment.  The  acid  transposes  the  surface  fibres  into  a  tough,  gela¬ 
tinous  mass  which  forms  a  protective  coating  for  the  unaltered 
fibres  beneath.  Such  paper  is  impervious  to  air  and  moisture.  In 
some  instances  zinc  chloride  is  substituted  for  the  sulphuric  acid. 
Its  action  is  quite  similar. 

In  the  manufacture  of  vulcanised  fibre,  used  for  trunks, 
tubs,  waste  baskets,  trucks,  etc.,  sheets  of  paper  which  have 
been  treated  with  zinc  chloride  are  pressed  together  and  then 
thoroughly  washed  to  remove  the  chemicals. 

Another  modification  of  parchment  paper  is  the  ll  illesden 
Paper  obtained  by  saturating  a  sheet  of  paper  with  Schweitzer  s 
reagent  (an  ammoniacal  solution  of  copper  oxide)  thus  causing 
a  gelatinization  to  take  place  on  the  outside  of  the  paper  so  that 
when  the  sheet  is  dried  it  is  impregnated  with  a  green  varnish 
consisting  of  a  compound  of  the  reagent  with  the  cellulose,  which 
is  waterproof  and  very  strong.  Sometimes  several  sheets  are 
pressed  together,  making  a  board.  The  reagent  is  prepared  on 
a  commercial  scale  by  allowing  concentrated  ammonia  liquor 


MODERN  PULP  AND  PAPER  MAKING 


50 

to  trickle  down  towers  packed  with  copper  scrap,  air  being  blown 
up  the  towers  at  the  same  time.  The  same  treatment  is  applied  to 
textiles.. 

In  the  manufacture  of  these  different  forms  of  parchment 
paper  it  is  advisable  to  use  a  bleached  stock  and  inadvisable 
to  use  mechanical  wood  pulp.  Unbleached  stock,  when  treated 
with  these  chemicals,  takes  on  a  dirty,  brown  color.  The  presence 
of  mechanical  wood  pulp  is  apt  to  give  a  charred  effect.  Formerly 
an  unsized  cotton  rag  stock  was  entirely  used  for  making  these 
special  grades,  but  this  is  now  supplanted  almost  entirely  by  the 
use  of  bleached  sulphite  stock. 

Newsprint. 

The  importance  of  the  newsprint  branch  of  the  paper  in¬ 
dustry  can  be  gauged  when  we  note  that,  according  to  the  United 
States  Census  of  1914,  there  were  at  that  time  some  2,500  daily 
and  Sunday  and  about  14,000  weekly  and  semi-weekly  newspapers 
in  the  United  States.  According  to  the  census  data  the  daily 
papers  had  a  circulation  of  about  30,000,000  copies,  the  Sunday 
papers  about  17,000,000  and  the  weekly  and  semi-weekly  papers 
about  24,000,000.  The  size  of  the  papers  and  the  consequent  con¬ 
sumption  of  newsprint  has  shown  a  constant  increase.  In  1899 
the  United  States  produced  569,212  tons  of  newsprint,  and  in 
1916  1,355,196  tons.  As  shown  in  the  Census  of  1914,  news¬ 
print  formed  one-fourth  of  the  total  paper  tonnage  of  the  United 
States  and  about  one-sixth  of  the  total  value  of  paper  produced. 
Only  a  very  small  part  of  the  newsprint  produced  in  the  United 
States  is  exported  (in  1916  only  about  75,000  tons)  and  in  addi¬ 
tion  large  amounts  are  imported  from  Canada  (in  1918  about 
560,000  tons,  or  about  75  per  cent  of  the  total  Canadian  produc¬ 
tion)  and  a  little  from  other  countries. 

The  uses  of  newsprint  are  by  no  means  confined  to  the  print¬ 
ing  of  newspapers.  Large  amounts  are  used  for  catalogs,  tele¬ 
phone  directories,  railway  guides,  school  tablets,  scratch  pads, 
handbills,  wrapping  paper,  etc. 

Most  newsprint  is  made  entirely  of  ground  wood,  or  ground 
wood  with  about  20  per  cent  of  sulphite  added.  In  all  cases 
unbleached  stock  is  used.  In  the  manufacture  of  this  paper 
it  is  necessary  to  run  the  machine  at  high  speed,  and  since  a 
sheet  of  newsprint  is  comparatively  light,  it  necessitates  the  use 
of  comparatively  slow  stock.  The  explanation  of  this  will  become 
apparent  after  the  chapter  on  the  machine  room  has  been  studied. 
Some  modern  newsprint  machines  run  at  a  speed  in  excess  of 
900  feet  per  minute  and  make  a  sheet  more  than  150  inches  wide 
— in  some  cases  as  wide  as  199  inches. 

Blotting  Paper. 

By  reason  of  the  physical  properties  of  cotton  fibre  which  has 
the  greatest  capacity  for  sucking  up  liquids  of  any  of  the  fibres 


VARIETIES  OF  PAPER 


51 


used  in  the  manufacture  of  paper,  the  best  blotting  papers  are 
invariably  composed  of  cotton  rag  stock.  Before  treating  the 
stock  in  the  beaters  it  is  essential  to  allow  it  to  become  well  ma¬ 
tured  and  it  is  frequent  practice  to  allow  tbe  rag  stock  to  sour 
after  boiling  in  order  that  any  lime  salts  that  have  been  left 
may  become  decomposed.  For  this  process  a  pure,  soft  water  is 
essential,  since  calcium  salts  have  a  tendency  to  harden  the  fibre 
and  render  it  less  absorbent. 

Just  as  in  other  grades  of  paper  there  are  many  gradations 
in  quality  from  the  best  blotters  made  of  pure  cotton  rag  stock 
to  cheap  blotters  made  almost  entirely  of  mechanical  wood 
pulp.  In  the  medium  grades  soft  soda  pulp,  either  alone  or 
with  an  admixture  of  cotton  rag  pulp,  is  extensively  used. 
Blotting  stock  is  beaten  quickly,  the  beater  being  of  ample  capac¬ 
ity  so  the  circulation  will  be  rapid  and  thorough.  Usually  one 
hour  in  the  beater  is  enough. 

The  principal  requirements  of  good  blotting  paper  are;  ab¬ 
sorbency,  freedom  from  hairiness  and  a  good  printing  surface. 
Hairiness  gives  rise  to  fluff  that  tends  to  cause  smudging  of 
the  ink.  A  good  blotting  paper  should  only  yield  a  slight  quan¬ 
tity  of  ash  on  being  incinerated. 

Filter  Paper. 

Filter  paper  is  in  many  respects  similar  to  blotting  paper. 
Just  as  in  blotting  paper,  the  fundamental  requirement  is  marked 
ability  to  absorb  water  and  other  liquids.  The  manufacture  of 
filter  paper  for  scientific  purposes  is  a  branch  of  paper  manu¬ 
facture  which  has  received  most  expert  attention  and  forms  an 
art  in  itself.  There  are  a  number  of  firms  in  England,  France, 
Germany  and  Sweden  that  have  given  special  study  to  this 
subject  and  produced  a  wide  variety  of  filter  papers  suitable 
to  the  various  requirements  of  the  chemist.  For  some  purposes 
a  very  fast  filtering  paper  is  required,  i.  e.,  one  that  will  let  the 
liquid  run  through  in  a  minimum  of  time,  and  this  effect  is 
sometimes  secured  at  the  expense  of  making  the  paper  so  loose 
and  open  in  structure  as  to  allow  some  of  the  finer  particles  of 
the  precipitate  to  pass  through.  For  other  purposes  papers  are 
required  which  will  make  as  near  a  100  per  cent  retention  of 
the  precipitate  as  possible,  even  if  the  filtering  operation  is  very 

slow.  .  ,  •  1  1 

A  good  filter  should  possess  sufficient  mechanical  strength, 

even  when  wet,  not  to  be  broken  by  the  weight  of  the  liquid  in 
the  filter  or  by  a  moderate  amount  of  suction.  Filter  papers 
intended  to  be  used  with  suction  naturally  have  to  be  stronger 
than  others.  A  good  filter  paper  should  have  a  smooth  surface 
free  from  hair  or  down  or  fluff  of  any  kind  that  will  detach 
itself  from  the  surface  of  the  paper  and  come  off  when  a  pre¬ 
cipitate  has  been  dried  in  it.  ,  r  1  i, 

The  best  filter  papers  consist  of  stock  made  from  the  best 


52  MODERN  PULP  AND  PAPER  MAKING 

qualities  of  cotton  rags,  sometimes  with  a  little  wool  fibre  mixed 
in.  In  order  to  extract  any  mineral  matter  in  the  fibre  (silica, 
etc.),  the  stock  is  treated  with  hydrochloric  and  hydrofluoric 
acids,  dilute  alkalis  and  frequent  washings  with  the  purest  water. 
The^extent  of  this  treatment  depends,  naturally,  on  the  ultimate 
quality  desired.  For  rough  qualitative  work  and  industrial  pur¬ 
poses  such  treatment  is  not  necessary.  For  filters  for  accurate 
quantitative  analytical  work  (e.  g.  the  ashless  filters),  such 
treatment  is  necessary.  Such  filter  paper  is  almost  perfectly 
pure  cellulose. 

After  being  made  into  sheets,  filter  paper  is  ordinarily  stamped 
out  in  disks  of  various  diameters,  which  are  packaged  together 
in  bundles  for  sale.  A  good  deal,  however,  is  sold  in  sheet  form. 
The  hpvier  grades  are  sold  in  large  sheets  for  filter  presses  and 
other  industrial  work. 

Considerable  quantities  of  filter  paper  stock  are  never  made 
into  paper  at  all,  being  dried  and  sold  in  bulk  form  for  “filter 
mass  ’  which  is  packed  into  various  forms  of  stoneware  and 
metallic  filtering  apparatus.  For  this  sort  of  filtering  medium 
sulphite  wood  pulp  has  been  found  to  be  an  effective  and  cheaper 
substitute  for  cotton  rag  pulp  in  some  lines  of  manufacture. 

Swedish  filter  paper  manufacturers  frequently  freeze  the 
wet  sheets  of  paper.  The  crystals  of  ice  force  apart  the  fibres 
leaving  the  paper  with  a.  porous  structure  when  it  is  thawed 
and  dried. 

Hangings. 

Wallpaper  stock  is  made  usually  from  a  mixture  of  85  per 
cent  ground  wood  and  15  per  cent  sulphite,  both  being  used  in 
the  unbleached  state.  About  10  per  cent  of  clay  is  added  to  the 
combination  in  order  to  render  it  opaque  and  give  a  suitable 
surface.  The  surface  must  be  capable  of  receiving  a  good  im¬ 
pression. 

Hanging  paper  must  be  sufficiently  well  sized  that  when  it  is 
applied  to  a  wall  it  will  stand  the  application  of  the  paste  with¬ 
out  breaking.  Undersized  hangings  are  very  objectionable.  Like 
all  other  classes  of  paper,  special  attention  must  be  given  to 
the  moisture  content  of  the  finished  paper.  If  it  is  over-dried, 
it  will  become  brittle  and  practically  worthless.  The  prime  feature 
to  look  for  in  hangings  is  softness  combined  with  pliability, 
resistance  to  water  and  a  certain  bulk. 

The  quality  of  the  product  of  a  mill  making  hangings  depends 
largely  on  its  ground  wood  department.  Good  hangings  are 
made^  in  the  ground  wood  mill.  Without  properly  made  stock 
it  is  impossible  to  manufacture  a  good  product,  no  matter  how 
much  care  is  exercised  in  subsequent  operations.  In  no  branch 
of  paper  making  is  this  more  true. 

Since  this  is  necessarily  a  comparatively  cheap  grade  of  paper, 
and  thus  it  is  necessary  to  run  the  machine  at  a  high  rate  of 


VARIETIES  OF  PAPER 


53 


speed  (in  order  to  have  an  output  of  finished  paper  that  will 
yield  sufficient  dividends)  ground  wood  stock  of  a  very  free 
nature  must  be  employed  since  the  paper  is  a  comparatively  heavy 
sheet.  If  slow  stock  is  used,  the  machine  must  be  slowed  down 
to  get  the  water  out  of  the  sheet.  This  results  in  a  loss  in 
production  serious  in  the  case  of  an  inexpensive  product.  It  is 
therefore  essential  that  the  ground  wood  stock  should  be  pre¬ 
pared  in  a  free  state  as  closely  resembling  sulphite  fibres  as 
possible.  The  details  of  accomplishing  this  effect  will  be  ex¬ 
plained  in  the  chapter  dealing  with  the  ground  wood  mill. 

The  users  of  hangings,  or  wall  paper  stock,  have  adopted  as 
standard  certain  weights  of  paper,  as  follows : 

Basis  Weight 

Weight  in  Ounces  24  in.  x  36  in. —  480  sheets 


9 

34 

10 

42 

II 

44 

12 

48 

14 

58 

15 

60 

16 

62 

18 

74 

Surface  of  Paper:  9  yards  long  x  19^  inches  wide. 

Roofing  and  Building  Papers. 

These  papers  are  made  from  very  coarse  and  cheap  materials 
such  as  low  grade  rags,  old  gunny  sacks,  coarse  jute  wastes,  sul¬ 
phite  screenings,  etc.  The  principal  points  aimed  at  are  cheap¬ 
ness  and  bulkiness,  together  with  a  certain  absorbency,  which  is 
necessary  when  the  papers  are  to  be  impregnated  with  asphalt, 
etc. 

In  addition  to  ordinary  building  and  roofing  papers,  a  large 
number  of  specialties  containing  asbestos,  etc.,  and  impregnated 
with  various  chemicals  and  asphaltic  substances  have  been  de¬ 
veloped.  In  some  cases  the  papers  are  marketed  in  rolls  and 
in  other  cases  handled  as  boards. 

The  machines  for  making  these  boards  are  very  highly  spe¬ 
cialized  and  are  generally  of  the  cylinder  type.  The  principle  and 
operation  of  such  equipment  will  be  described  in  the  chapter  on 
the  machine  room. 


IV. 


The  Saw  Mill. 


At  first  sight  the  saw  mill  might  not  seem  to  really  be  part 
of  the  pulp  mill  at  all,  but  as  we  proceed  to  study  in  detail  the 
manufacture  of  pulp,  and  later  of  paper,  we  will  see  that  the 
preliminary  steps  necessary  to  the  suitable  preparation  of  wood 
for  further  processes  of  manufacture  have  a  very  direct  bear¬ 
ing  on  the  quality  of  the  pulp  and  the  paper  produced,  and  that 
the  efficiency  of  the  saw  mill  department  is  vitally  connected 
with  the  efficiency  of  the  plant  as  a  whole. 

The  saw  mill  comprises  a  collection  of  machinery  for  bring¬ 
ing  the  logs  into  the  mill,  reducing  them  to  a  uniform  short  length 
(usually  either  2  or  4  feet)  and  delivering  them  to  the  wood 
room  (described  in  the  next  chapter)  where  the  bark  is  removed 
and  the  wood  is  converted  into  chips. 

In  addition  to  sawing  equipment,  the  saw  mill  naturally  re¬ 
quires  conveyor  systems  so  adapted  as  to  handle  the  various 
materials  at  a  minimum  of  labor  and  expense. 

Log  Haul-Ups,  or  Jack  Ladders. 

Whenever  possible,  it  is  advisable  to  use  parallel  chain  haul- 
ups,  which  bring  the  logs  up  sideways,  instead  of  end  for  end. 
This  form  of  hauling  is  especially  advisable  when  the  logs  are  of 
uniform  length  and  are  to  be  cut  into  blocks  with  a  multiple 
saw  slasher. 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 


Fig.  7. — Parallel  chain  log  haul-up. 

The  diagram  shows  the  arrangement  of  such  a  system.  Two 
or  more  chains  are  used,  running  parallel  to  one  another.  The 
logs  are  floated  into  such  a  position  that  they  will  be  pulled 
up  by  the  chains  as  these  emerge  from  the  water.  The  incline 
should  not  be  more  than  30°  if  24-inch  logs  or  larger  are  to  be 

54 


THE  SAW  MILL 


55 


handled.  Smaller  logs  can  safely  be  handled  at  a  greater  angle. 
In  fact,  24-inch  logs  can  be  handled  at  angles  exceeding  30°  if 
specially  designed  chains  are  provided.  The  above  remarks 
refer  to  the  usual  forms  of  chains,  two  typical  kinds  of  which 
are  illustrated. 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  8. — Steel  wing  link  chain. 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y, 


Fig.  9. — Iron  wing  link  chain. 

The  logs  discharge  automatically  from  the  head  end  of  the 
haul-up  onto  an  inclined  deck,  and  roll  onto  the  slasher.  Auto¬ 
matic  counting  devices  are  sometimes  installed  which  record 
the  number  of  logs  passing,  and  thus  afford  accurate  records  of 
the  numbers  of  logs  brought  into  the  mill  from  day  to  day. 

When  it  is  found  more  convenient  to  bring  the  logs  up  end  to 
end,  an  endless  chain  haul-up  is  installed,  as  shown  in  the  illus¬ 
tration.  Several  types  of  chain  are  used  on  such  conveyors, 
three  of  which  we  illustrate. 

The  lower  end  of  the  haul-up  should  be  so  arranged  that 
it  can  be  raised  and  lowered,  thus  accommodating  the  chain  to 
various  levels  of  water  met  with  during  a  season’s  operations. 

The  illustration  shows  the  drive  for  this  haul-up  located 
above  the  floor.  This  is  not  imperative.  It  can  very  conveniently 
be  located  below  the  floor.  The  drive  can  be  either  spur  or 
bevel  gear,  and  starting  and  stopping  is  usually  provided  for  by 
means  of  iron  and  leather  frictions,  or  by  means  of  a  belt  tight¬ 
ener. 


56 


MODERN  PULP  AND  PAPER  MAKING 


Courtesy:  Ryther  S'  Pringle  Co.,  Carthage,  N.  Y.  ^ 

Fig.  lo. — Endless  chain  haul-up. 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  IT. — Typical  chains  used  with  endless  chain  haul-up. 


THE  SAW  MILL 


57 


Log  Kickers. 

When  logs  are  brought  into  the  mill  end  to  end,  a  kicker 
must  be  used  to  expel  them  from  the  log  haul  trough.  The 
usual  form  of  this  machine  is  a  rocker  shaft,  to  which-  as  many 
cast  iron  arms  are  attached  as  may  be  required  (this  depending 
on  the  length  of  the  logs  being  handled).  To  these  arms  are 
attached  shover  arms,  which  are  made  up  of  two  castings  with 
heavy  wrought  iron  riveted  sides,  working  through  cast  iron 
guide  troughs,  located  at  the  side  of  the  log  haul  trough.  The 
rocker  shaft  and  arms  are  in  turn  operated  by  means  of  a  steam 
cylinder,  attached  to  the  shaft  by  a  connecting  rod  or  pitman. 
This  machine  may  be  operated  by  means  of  a  foot  tread  or  lever. 
In  most  cases  the  former  device  is  used  and  the  tread  placed  on 
one  side  of  the  log  way.  The  operator  by  stepping  on  the  tread 
admits  steam  to  the  cylinder,  and  throws  the  logs  out  of  the 
trough  onto  the  inclined  deck  leading  to  the  live  rolls.  The 
shover  arms  pass  up  through  the  guide  troughs  in  such  a  manner 
as  to  strike  the  log  at  the  easiest  point  to  set  it  rolling.  The 
cylinder  is  stationary,  steam  piping  rigid  and  all  possibility  of 
leaky  cylinders  thereby  avoided. 

Saws. 

There  are  two  chief  types  of  saws  used  in  saw  mills  in 
the  paper  industry.  These  are :  ( i )  Slashers,  which  are  intended 
for  the  economical  reduction  of  long  logs  of  nearly  uniform 
length  to  blocks  of  a  short  uniform  length  in  large  quantities. 
(2)  Swing  Sazvs,  which  are  intended  for  use  in  mills  where  the 
logs  are  of  extreme  length,  or  where  the  lengths  vary  to  such 
a  degree  as  to  render  a  slasher  impracticable.  In  many  saw 
mills  both  slashers  apd  swing  saws  are  required. 

Slashers. 

These  machines  consist  of  an  arrangement  of  one  or  more 
stationary  saw  arbors  equipped  with  the  ordinary  type  of  cir¬ 
cular  saw,  revolving  at  a  high  rate  of  speed  and  mounted  upon  a 
slightly  inclined  table.  This  table  is  provided  with  a  number 
of  feed  chains,  so  arranged  as  to  receive  the  logs  automatically 
from  an  inclined  deck,  carry  them  to  and  through  the  saws,  and 
deliver  them  at  the  upper  end  to  a  conveyor  or  whatever  other 
means  may  be  provided  for  removing  them. 

The  arbors  should  be  made  of  the  best  quality  of  cold  rolled, 
open  hearth  steel,  of  superior  quality  and  temper,  combining 
both  strength  and  stiffness.  The  arbors  themselves  should  be 
accurately  turned  and  keystead,  and  the  saw  collars  fitted  with 
the  utmost  care.  The  diameter  of  the  arbors  should  be  exactly 
the  same  throughout  the  entire  length. 


58 


MODERN  PULP  AND  PAPER  MAKING 


Each  arbor  should  be  equipped  with  three  self-oiling  bearings 
of  liberal  strength.  Two  of  these  bearings  should  be  attached  to 
the  framework  of  the  slasher,  and  one'  bearing  should  be  mounted 
in  an  adjustable  floor  stand  and  arranged  to  be  placed  outside 
of  the  arbor  pulley,  thus  insuring  a  perfect  and  permanent  align¬ 
ment  of  the  arbor. 

The  arbor  pulleys  should  be  all  made  extra  heavy  and  solid, 
turned  and  perfectly  balanced,  keyed  and  fitted  to  the  arbors. 

The  saw  collars  should  be  made  of  cast  iron,  and  when  fitted 
for  6o-inch  saws  should  be  lo  inches  in  diameter,  with  a  2-inch 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  12. — Typical  five-saw  slasher  installed  in  wood  preparing  plant. 


arbor  hole  and  two  lug  pins,  inch  diameter  and  MA  inches 
center  to  center.  The  tight  collar  is  fitted  against  a  slight  shoulder 
turned  on  the  arbor  and  then  shrunk  on.  The  loose  collar,  which 
clamps  the  saw  against  the  tight  collar,  is  secured  by  means  of  a 
2-inch  hexagon  nut,  fitted  with  a  special  thread  to  permit  of 
securely  clamping  the  saw.  The  above  arrangements  are  neces¬ 
sary  to  guard  against  any  danger  of  the  saws  working  loose 
while  in  operation. 

The  saw  arbors  are  arranged  in  such  a  manner  relative  to  the 
feed  chains  and  other  parts  of  the  slasher  that,  by  merely  re¬ 
moving  the  nut  and  the  loose  collar,  the  saws  may  be  changed 
very  quickly,  without  removing  the  arbors  or  any  other  part 
of  the  machine. 

The  feed  chains  are  a  very  important  part  of  the  slasher. 
They  run  parallel  with  the  saws,  pick  up  the  logs  at  the  receiving 


THE  SAW  MILL 


59 


end  of  the  machine,  carry  them  to  and  through  the  saws,  and 
deliver  them  sawed  to  length  at  the  discharge  end  of  the  ma¬ 
chine. 

The  nature  of  these  chains  will  readily  be  seen  from  the 
illustrations.  The  shape  of  the  pockets  formed  by  the  link  is 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N,  Y. 

Pig_  13. — Detail  of  slasher  chain. 


such  that  a  log  of  any  diameter  from  4  inches  to  24  inches  is 
firmly  held  in  position  while  being  sawed,  thus  avoiding  any 
possible  cramping  of  the  saws.  There  are  two  lines  of  chain 
for  each  sawed  piece  resulting  from  the  sawing  of  the  log,  thus 
providing  for  securely  holding  in  position  each  block  of  wood 
throughout  the  cut  and  until  the  blocks  are  released  at  the  head 

end  of  the  machine.  .  ,  1  1  • 

When  passing  the  sprockets  at  the  delivery  end,  the  chains 

free  the  blocks  of  sawed  wood  automatically,  and  they  are  de¬ 
livered  onto  the  conveyor,  or  whatever  means  may  have  been 
provided  for  removing  them.  The  chains  should  run  in  steel 
trough  irons,  to  which  are  riveted  cast  iron  chairs,  by  which 
they  are  secured  to  the  frame  of  the  machine.  The  chains  must 
be  accurately  built  to  template,  so  that  when  there  are  a  number 
of  chains  used,  the  alignment  of  the  chain  pockets  will  be  perfect, 
thus  bringing  the  logs  squarely  against  each  saw. 

*  The  sprocket  wheels  which  drive  the  feed  chains  should  be  ot 
cast  iron  with  chilled  teeth  surfaces  to  insure  jong  li  e.  le 
head,  or  driving  sprockets,  should  be  keyed  to  the  head  shaft  par¬ 
ticular  care  being  used  to  preserve  a  perfect  alignment  of  the 
sprockets,  and,  in  consequence,  the  chains  themselves. 

The  head  shaft,  to  which  the  driving  sprockets  are  keyed, 
should  be  back-geared  through  a  pinion  countershaft,  from  a 


6o  MODERN  PULP  AND  PAPER  MAKING 

belt  countershaft,  which,  in  turn,  is  driven  from  a  pulley  keyed 
to  one  of  the  arbors.  In  this  manner,  the  speed  of  the  feed 
chains  is  reduced  to  about  25  feet  per  minute.  This  feed  should 
be  self-contained  and  capable  of  being  started  or  stopped  instantly, 
independently  of  the  saws  by  a  hand  lever. 

In  large  slashers,  where  the  chains  are  of  great  length,  it  is 
advisable  to  provide  bottom  idlers  to  relieve  the  driving  sprocket 
of  the  weight  of  the  chains. 

One  prominent  manufacturer  of  this  class  of  equipment  states 
that,  as  the  result  of  a  number  of  observations  taken  from  differ¬ 
ent  slashers  working  under  varying  conditions,  the  following 
definite  statement  can  , be  made  as  to  the  power  required  to 
operate  the  same  successfully : 

“Eighteen  H.  P.  should  be  figured  for  each  60-inch  saw  op¬ 
erated  to  full  capacity.  This  amount  of  power  will  also  operate 
the  necessary  log  haul,  or  jack  ladder,  required  to  bring  the  logs 
to  the  slasher.  For  .saws  less  than  60  inches  diameter,  the 
power  required  will  be  proportionately  less.” 

According  to  the  writer’s  experience,  the  above  figure  is  cor¬ 
rect.  The  power  required  for  the  log  haul,  or  jack  ladder,  de¬ 
pends  on  the  length  and  pitch  of  the  ladder.  Under  ordinary 
conditions  a  15  H.  P.  motor  will  take  care  of  a  jack  ladder  75 
feet  from  center  to  center^-of  sprockets. 

The  following  two  descriptions  of  the  saw  mill  equipment 
installed  in  two  well  known  pulp  mills  by  Messrs.  Ryther  & 
Pringle  Company,  of  Carthage,  N.  Y.,  are  typical: 

At  a  plant  in  New  York,  the  logs,  which  are  12  feet  long, 
are  brought  into  the  mill  by  a  parallel  chain  log  haul  and  de¬ 
livered  automatically  to  the  slasher  which  is  equipped  with  five 
60-inch  saws  so  arranged  as  to  cut  the  12-foot  logs  into  six  24- 
inch  pieces.  The  sawn  blocks  are  delivered  automatically  from 
the  head  end  of  the  slasher  to  a  cable  conveyor,  which  in  turn 
carries  them  to  a  storage  pile  outside  the  mill. 

This  machine  (Fig.  14)  is  operated  with  a  crew  of  eleven 
men,  distributed  as  follows :  Seven  men  are  stationed  at  the  foot 
of  the  log  haul  to  guide  the  logs  onto  the  elevator  chains,  two 
men  are  on  the  slasher  itself,  and  the  other  two  men  are  on  the 
cable  conveyor  which  carries  the  sawn  wood  away  from  the 
slasher.  The  direct  labor ‘cost  resulting  from  this  arrangement 
(Note:  this  statement  made  in  1912)  is  less  than  3  cents  per 
cord,  and  includes  all  of  the  labor  necessary  to  take  the  logs 
from  the  river,  cut  them  to  24-inch  lengths,  and  deliver  them  to 
the  storage  pile. 

During  four  seasons  this  machine  handled  163,000  cords  of 
wood,  the  daily  average  being  about  500  cords  per  ten  hours. 
The  total  amount  of  repairs  and  replacements  for  that  period 
averaged  less  than  $5.00  per  season.  The  saws  did  not  have  to 
be  changed  in  four  years,  during  which  time  they  wore  from 
60-inch  diameter  to  55^  inch  diameter. 


THE  SAW  MILL 


6i 


Indicator  diagrams  taken  at  the  above  plant  at  various  inter¬ 
vals  during  the  operations  showed  a  total  power  consumption 
of  not  to  exceed  90  H.  P.  which  included  the  power  necessary 
to  operate  the  entire  combination  of  log  haul  and  slasher. 

A  similar  machine  installed  at  a  Canadian  plant  exceeded  the 
record  of  the  above  machine,  owing  to  more  favorable  river  con- 


3 

I 

r 


Courtesy :  Ryther  &  Pringle  Co.,  Carthage,  N,  Y, 


Fig.  14. — Plan  and  elevation  of  wood  preparing  installation  consisting  of 
five-saw  slasher,  parallel  chain  log  haul-up  and  distributing  conveyor. 
This  is  the  same  installation  shown  in  Fig.  12. 


ditions.  The  average  at  the  Canadian  mill  was  over  600  cords 
per  ten  hours.  On  one  day  as  high  as  16,815  logs  were  put  over, 
this  being  more  than  860  cords  per  ten  hours. 

At  another  Canadian  plant  a  seven  saw  slasher  is  iristailed. 
Owing  to  the  location  of  the  wood  room  relative  to  the  pond  from 
which  the  logs  were  drawn  it  was  necessary  in  this  instance  to 


62  MODERN  PULP  AND  PAPER  NIAKING 

take  the  logs  from  the  water  endwise,  by  means  of  a  single  strand 
log  haul,  instead  of  broadside  by  a  parallel  chain  log  haul,  as  is 
ordinarily  done.  Operating  in  this  manner  it_  was  not  possib  e 
to  cut  as  large  a  number  of  logs  per  hour  as  is  done  where  the 

narallel  chain  log  haul  is  used.  ,  ,  j 

^  One  man,  stationed  at  the  table  where  the  log  haul  delivered 

the  logs  from  the  pond,  commanded  a  view  of  the  entire  opera¬ 
tion  from  the  water  to  the  conveyor  for  sawn  blocks  and  con¬ 
trolled  the  log  chain  and  the  kicker  to  the  slasher  and  counted 
the  logs  The  kicker  throws  the  logs  from  the  log  haul  trougi 
to  the  slasher  table,  and  at  the  same_  time,  lines  up  the  logs  so 
that  the  head  ends  follow  a  regular  line  through  the  saws.  The 
last  end  of  the  logs  is  trimmed  first  to  i6  feet,  plus  a  slight  al- 
owance  for  sawdust  loss.  The  first  saw  cuts  the  i6-foot  logs 
once  in  two  and  spreads  the  logs  sufficiently  to  prevent  any  pos¬ 
sibility  of  cramping  the  saw  ahead.  Next  the  two  8-foot  block 
are  elch  cut  into  two  4-foot  pieces,  and  finally  another  pair  of 
saws  cut  each  4-foot  block  once  more  m  two,  thus  resulting  m 
eight  24-inch  pieces.  From  5,000  to  6,000  logs  can  be^ handled 
from  the  water,  sawed  and  piled  m  10  hours.  The  handling, 
sawing  and  piling  of  the  logs  in  24-mch  lengths  is  done  at  a 
cost  (in  1912)  for  labor  of  10  cents  per  cord.  •  , 

It  should  be  taken  into  consideration  that  a  great  variety  of 
factors,  apart  from  the  efficiency  of  the  machinery,  influence 

the  operation  of  such  an  installation.  ^  .  •  i.  11 

It  is  not  always  possible,  for  a  variety  of  reasons,  to  mstal 
the  machinery  in  the  position  and  arrangement  ideal  from  a 
mechanical  point  of  view.  The  case  of  the 
scribed  above,  is  an  illustrat;on  of  this.  In  such  cases  the  best 

has  to  be  made  of  the  conditions  at  hand. 

River  conditions  will  have  a  great  effect  on  the  problems 
of  the  saw  mill,  and  these  will  not  be  the  same  at  any  two  plan  s, 
and  will  vary  at  one  and  the  same  plant  from  time  to  tune. 

The  labor  available  at  different  points  wil  vary.  _  The  opera¬ 
tion  of  this  kind  of  equipment  requires  both  physical  strength 
and  intelligence,  as  well  as  ingenuity.  It  will  be  to  pay  t 

have  this  department  overmanned,  if  anything,  rather  than  under¬ 
manned. 

Swing  Saws. 

'Where  logs  of  varying  lengths  and  diameters  have  to  be  re¬ 
duced  to  short  blocks  of  uniform  length,  a  swing  saw  system  is 

^^”We^ogs  are  brought  into  the  mill  end  for  end.  by  means  of 
a  single  strand  conveyor  chain  fitted  with  spurred  links  at  in¬ 
tervals.  The  log  haul  drive  is  so  arranged  as  to  be  under  the 
control  of  an  operator  stationed  at  the  ^^ead  of  the  log  deck, 
and  may  be  stopped,  or  started,  as  required.  A  log  haying  been 
brought^ to  the  hLd  of  the  deck,  the  drive  is  stopped  by  means 


THE  SAW  MILL 


63 

of  a  lever,  the  operator  admits  steam  to  the  kicker  cylinder,  and 
the  log  is  kicked,  or  rather  rolled,  from  the  trough  onto  the 
inclined  deck.  This  deck  is  of  sufficient  size  to  hold  in  reser\  3 
a  supply  of  logs.  From  the  deck,  as  required,  logs  are  re¬ 
leased  by  means  of  a  steam  trip,  or  loader,  and  roll  onto  the  live 
rolls.  The  live  rolls  are  arranged  to  operate  in  series — the  length 
of  the  train  over  all  being  sufficient  to  accommodate  the  longest 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  15. — Overhead  type  of  swing  saw  installation  showing  kickers  and 

slasher. 

logs  being  cut.  The  operation  of  these  live  rolls  is  under  the 
control  of  the  sawyer,  who  engages,  by  means  of  a  lever,  the 
frictions  which  drive  the  rolls,  and  advances  the  log  or  logs 
as  the  case  may  be  to  the  gauge  block.  The  gauge  block  is  located 
at  a  distance  beyond  the  saw  to  correspond  with  the  required 
length  to  be  cut,  and  as  soon  as  the  log  is  brought  in  contact  with 
the  gauge  block  and  stopped,  the  block  disappears.  The  sawyer 
then,  by  means  of  a  lever,  admits  steam  to  the  cylinder,  which 
operates  the  saw  frame,  bringing  the  saw  through  the  log  until 
the  cut  is  completed.  The  sawn  block  is  then  kicked  onto  the 
conveyors. 

Care  of  Saws  ^ 

It  is  very  important  that  the  saws  should  be  kept  in  the  best  of 
condition.  If  too  much  sawdust  is  produced  and  if  it  is  allowed 

’  Adapted  from  Lumberman’s  Handbook:  Henry  Disston  &  Sons,  Inc. 


MODERN  PULP  AND  PAPER  MAKING 


64 

to  adhere  to  the  ends  of  the  blocks  it  will  cause  trouble  later  on. 
Holes  and  defects  in  the  paper  can  sometimes  be  traced  right 
back  to  the  saw  mill. 

The  following  are  some  of  the  causes  which  give  rise  to  un¬ 
satisfactory  conditions  in  saw  mills.  Frequently  the  saw  or  the 


Fig.  16. — Another  swing  saw  installation  in  which  the  under-cut  type 

of  frame  is  used. 


saw  maker  is  blamed  when  actually  one  or  riiore  of  the  follow¬ 
ing  circumstances  is  the  cause  of  the  unsatisfactory  operation : 

Insufficient  power  to  maintain  regular  speed. 

Too  thin  a  saw  for  the  class  of  work  required. 

Not  enough  for  too  many  teeth  for  the  amount  of  feed 
carried. 

Weak  and  imperfect  collars. 

Collars  not  large  enough  in  diameter. 

Ill-fitting  mandrel  and  pin  holes. 

Uneven  setting  and  filing. 

Not  enough  set  for  proper  clearance. 

Too  much  pitch  or  hook  of  teeth. 

Irregular  and  shallow  gullets. 

Out  of  round  and  consequently  out  of  balance. 

A  sprung  mandrel,  or  lost  motion  in  mandrel  boxes. 

A  carriage  track  neither  level  nor  straight. 

Carriage  not  properly  aligned  with  saw. 

Lost  motion  in  carriage  trucks. 

Heating  of  journal  next  to  saw. 


THE  SAW  MILL 


65 


Guide-pins  too  tight  or  not  properly  adjusted. 

Backs  of  teeth  too  high  for  clearance. 

Attempting  to  run  too  long  without  sharpening. 

Setting  the  Carriage  Track  and  Husk  or  Saw  Frame:  It  is 
vfry  essential  to  good  work  that  the  foundation  of  the  mill  should 
be  amply  strong  to  withstand  the  shocks  it  is*  subjected  to  in 
turning  logs;  the  track  stringers  should  be  good  sound  heart 
lumber,  preferably  Yellow  Pine,  as  this  is  a  firm  wood  and  will 
resist  moisture.  The  size  of  the  stringers  should  not  be  less 
than  8  inches  by  8  inches  and  as  few  pieces  as  possible  to  make 
up  the  necessary  length.  The  stringers  should  be  set  perfectly 
level  and  parallel  with  the  mill  house  and  gained  into  the  girders, 
and  joists  of  the  mill  floor  or  foundation  timbers,  and  secured 
by  keyes  and  bolts  so  that  they  will  not  change  position  when 
logs  are  rolled  against  the  head  blocks.  The  track  irons,  par¬ 
ticularly  the  V  side,  should  be  firmly  bolted  to  the  stringer  and 
when  finished  be  perfectly  straight  and  level. 

It  is  quite  as  important  that  the  saw  frame  should  be  firmly 
secured  to  its  place  as  that  it  should  be  level  and  solid,  for  the 
vibration  and  strain  are  of  such  a  nature  that  the  frame  would 
quickly  change  position  unless  very  firmly  secured.  The  slight¬ 
est  change  would  make  a  vast  difference  in  the  running  of  the 
saw  and  necessitate  relining.  When  putting  in  the  husk  stringers, 
use  well  seasoned  wood  and  put  them  down  in  such  a  manner 
that  they  cannot  possibly  change  their  position,  then  find  the 
position  of  the  husk  on  the  stringers  and  fasten  down  securely 
with  through  bolts. 

Lining  the  Saiv  with  the  Carriage:  The  amount  of  lead 
required  for  circular  saws  should  be  the  least  amount  that  will 
keep  the  saw  in  the  cut  and  prevent  it  heating  at  the  center.  ^  If 
the  lead  into  the  cut  is  too  much,  the  saw  will  heat  on  the  rim ; 
if  the  lead  out  of  the  cut  is  too  much,  the  saw  will  heat  at  the 
center,  it  is  therefore  advisable  to  give  the  least  amount  that  is 
used,  which  is  one-eighth  of  an  inch  in  twenty  feet. 

Of  the  various  methods  used  for  lining  a  saw  with  the  car¬ 
riage,  the  following  is  the  one  thdt  we  think  will  be  the  most 
easily  understood:  First,  see  that  the  mandrel  is  set  perfectly 
level,  so  that  the  saw  hangs  plumb  and  true  when  screwed 
between  the  collars,  and  is  flat  on  the  log  side.  Draw  a  line 
running  ten  feet  each  way  from  center  of  mandrel  and  parallel 
with  the  V  track,  fasten  a  stick  to  the  head-block,  so  that  it 
comes  up  to  the  line  at  the  end  in  front  of  saw ;  run  carriage 
forward  the  twenty  feet,  move  the  rear  end  of  line  one-eighth  of 
an  inch  away  from  former  parallel  position,  then  slew  the  end 
of  mandrel  either  forward  or  backward  until  it  is  exactly  at 
right  angles  to  the  new  position  of  line,  and  the  saw  parallel 
with  same. 

All  end  play  must  be  taken  out  of  the  mandrel  and  carnage 
trucks  when  lining  a  saw  to  the  carriage,  and  the  truck  must 


66  MODERN  PULP  AND  PAPER  MAKING 

be  laid  solid,  level  and  true,  so  that  the  carriage  will  run  straight 
and  smooth. 

Collars  for  Saws:  For  a  perfect  running  saw  it  is  indispens¬ 
able  to  have  the  collars  and  stem  of  mandrel  true  and  well  fitting; 
any  imperfection  in  these  points  is  multiplied  as  many  times 
as  the  saw  is  larger  than  the  collars;  they  should  fit  exactly,^ 

Large  saws  should  have  collars  that  have  a  perfect  bearing 
of  three-quarters  of  an  inch  on  the  outer  rim,  the  other  part 
clear,  as  they  hold  tighter  than  a  solid  flat  collar.  Examine  the 
collars  carefully  to  see  if  they  are  true,  if  not,  have  them  made 
so;  also  be  sure  that  stem  of  mandrel  fits  the  hole  nicely  and 
offers  no  obstruction  to  the  saw  slipping  easily  up  to  and  against 
the  fast  collar.  The  use  of  six  inch  collars  for  portable  and 
semi-portable  mills  is  advocated.  Collars  for  steam  feed  mills 
should  be  larger. 

Test  the  saw  with  a  straight  edge,  and  if  it  is  found  true,  place 
it  on  the  mandrel,  tighten  up  the  collars  with  the  wrench,  test 
again  with  a  straight  edge  and  see  if  the  position  of  the  blade  has 
been  altered ;  observing  whether  it  shows  true,  if  not,  the  fault  is 
sure  to  lie  in  the  collars  and  will  be  likely  to  ruin  the  saw.  The 
best  results  cannot  be  obtained  from  the  mill  until  the  defects 
are  remedied. 

The  best  circular  saws  are  finished  by  a  process  which  in¬ 
sures  each  side  of  the  saw  plate  being  perfectly  true  throughout 
its  entire  surface;  by  this  invaluable  process,  every  particle  of 
unevenness  is  removed;  the  saw  never  requires  packing  (pro¬ 
viding  the  collars  are  true)  and  all  the  trouble  which  has  hitherto 
perplexed  the  sawyer  in  this  particular  is  removed. 

Adjusting  Saiv  to  Mill:  See  that  the  saw  slips  up  freely 
to  fast  collar  and  hangs  straight  and  plumb  when  tightened  up ; 
that  the  mandrel  is  level,  in  proper  line  with  the  carriage,  and 
that  it  fits  in  its  boxes  as  neatly  as  possible  without  heating, 
for  when  the  mandrel  heats,  by  transmission,  the  saw  will  heat 
also  and  thus  expand  in  the  centre,  which  will  make  it  work 
badly,  injure,  and  perhaps  ruin  it.  A  saw  cannot  be  expected 
to  run  on  a  mandrel  that  heats,  although  if  it  were  known 
exactly  to  what  degree  it  heats  a  saw  could  be  made  that  would 
admit  of  that  much  expansion.  However,  a  heating  mandrel 
will  always  give  more  or  less  trouble.  To  get  the  best  re¬ 
sults  from  a  saw  this  must  be  overcome. 

Take  up  all  end  play  or  lateral  motion  in  mandrel  as  the 
grain  of  the  wood  will  draw  or  push  the  mandrel  endwise,  no 
matter  how  well  the  saw  is  kept.  See  that  the  carriage  track  is 
level,  straight,  solid  and  in  proper  line,  also  that  rolls  or  trucks 
have  no  end  play.  Keep  all  gum  or  sawdust  off  the  tracks. 

Speed  of  Sazos:  This  is  a  very  important  point  for  con¬ 
sideration,  since  a  hundred  revolutions,  more  or  less,  will  al¬ 
ways  make  a  great  difference  in  the  running  of  the  saw.  The 
tension  of  saws  can  be  adjusted  to  overcome  a  slight  variation  in 


THE  SAW  MILL 


67 

speed  provided  full  instructions  are  given  when  ordering  the  saw 
though  we  would  advise  a  regular  speed  at  all  times.  Our  ex¬ 
perience  has  been  that  saws  work  better  when  run  at  a  regular 
speed  even  if  it  is  necessary  to  reduce  the  number  of  revolutions 
one  hundred  below  that  given  in  the  table,  than  to  have  a 
variable  speed.  If  the  power  is  too  light  to  maintain  the  stand¬ 
ard  speed,  run  the  engine  at  a  higher  regular  speed,  put  a  larger 
diameter  receiving  pulley  on  the  mandrel,  and  the  results  will 
be  better  both  as  to  quality  and  capacity.  This  will  be  much 
better  than  the  throttle  plan,  even  if  the  speed  does  fall  below 
that  given  in  the  table ;  the  regularity  is  the  most  desirable  point 
to  look  after.  Following  is  a  table  of  speeds; 


Speed  of  Saws  Running  10,000  ft.  per  Minute  on  the  Rim 


72 

in.,  530  revolutions  per 

min. 

36  in.. 

1080  revolutions  per  min. 

68 

“  560 

li 

i  i 

32  “ 

1225  “  “  “ 

64 

“  600 

n 

it 

28  “ 

1400  "  “ 

60 

“  640 

it 

a 

24  “ 

1630 

56 

“  700  “ 

it 

i  i 

.  20  “ 

i960  “  “ 

52 

“  750 

i  i 

i  i 

16  “ 

!!  ;;  ;; 

48 

“  815 

1 1 

it 

12  “ 

'  14  .1441 

44 

“  890 

1  ( 

t  i 

10  “ 

40 

“  980 

it 

a 

8  “ 

4600 

Portable  mills. 

of  limited  capacity,  are 

usually  run  at  a  speed 

about  one-third  less  than  given  above. 

Rules  for  Calculating  Speed,  etc. 

PROBLEM  I.  The  diameter  of  driving  and  driven  pulleys 
and  the  speed  of  driver  being  given,  find  the  speed  of  driven 
pulley. 

RULE.  Multiply  the  diameter  of  driver  by  its  number  of 
revolutions,  and  divide  the  product  by  the  diameter  of  the  driven ; 
the  quotient  will  be  the  number  of  revolutions  of  driven  pulley. 

PROBLEM  2.  The  diameter  and  revolutions  of  the  driven 
pulley  being  given,  find  the  diameter  of  the  driver. 

RULE. .  Multiply  the  revolutions  oi  driven  by  its  diameter 
and  divide  the  product  by  the  revolutions  of  the  driving  shaft , 
the  quotient  will  be  the  diameter  of  driver. 

Splitters. 

Sometimes  when  very  large  wood  is  being  handled,  which 
would  not  be  capable  of  being  put  into  the  chipper  spout,  or 
into  a  pulp  grinder,  a  device  known  as  a  splitter  is  employed 
to  separate  the  large  blocks  into  two  or  more  smaller  ones.  This 
machine  is  simply  a  mechanically  operated  axe  of  powerful  con¬ 
struction,  standing  about  10  or  12  feet  high.  The  natuie  o 
the  machine  will  be  readily  understood  from  the  illustration. 

Another  excellent  type  of  splitter^  is  of  a  horizontal  design. 
This  splitter  is  run  by  an  electric  motor,  belted  to  a  pulley. 

>See  “Paper,”  Vol.  21,  No.  14,  Dec.  12,  1917.  for  more  detailed  descriidion. 


Courtesy:  Ryther  S’  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  17. — Vertical  type  of  splitter. 

Power  tests  have  shown  that  7^  H.  P.  furnishes  ample 
power  for  splitting  4-foot  wood.  When  operating  normally 
splitters  will  sometimes  consume  no  more  than  3^4  to  4  horse¬ 
power.  In  cases  of  this  kind,  however,  it  is  always  well  to  be 
safe  and  furnish  too  large  a  motor  with  the  splitter  rather  than 
one  that  is  too  small.  A  10  H.  P.  motor  should  be  all  right.  The 
cost  of  the  power  is  a  very  small  matter  compared  with  the  in¬ 
creased  output  developed  by  a  good  splitter. 

The  base  of  the  horizontal  splitter  is  made  of  two  channels 
securely  bolted  to  heavy  cast  iron  cross  bars.  Heavy  cast  iron 


68  MODERN  PULP  AND  PAPER  MAKING 

Motor  drive  is  convenient  and  economical  because  it  is  in  use 
only  when  wanted  and  does  not  require  an  extra  attendant. 
The  motor  runs  continuously  during  the  splitting  process,  and  if 
for  any  reason  the  operator  wishes  to  stop  the  axe  he  merely 
shifts  a  hand  lever  which  operates  a  clutch  connecting  the  driving 
pulley  with  the  axe  mechanism. 


THE  SAW  MILL  '  69 

double  gear  shaft-bearings  are  mounted  on  the  channels  and 
are  made  to  receive  both  gear  and  pinion  shafts. 

A  heavy  cast  iron  splitting  block  is  mounted  on  the  channels 
securely  bolted  to  them,  thus  forming  part  of  the  base.  This 
block  is  slightly  rounded  and  has  a  corrugated  face  to  prevent 
the  wood  from  slipping  when*,  the  machine  is  in  operation.  It 
is  obvious  that  should  slipping  occur  in  any  way  the  operator 


Fig.  18. — Horizontal  type  of  splitter. 


would  be  in  danger.  The  double  shaft  bearings  and  splitting 
block  are  connected  by  steel  tie  rods.  The  axe  guides  are  mounted 
on  the  base  very  rigidly  and  consist  of  two  steel  slides  so  ar¬ 
ranged  and  fitted  that  the  axe  has  a  bearing  on  the  under  side 
as  well  as  on  the  steel  sides.  Experience  has  shown  that  it 
pays  to  use  plenty  of  bearing  surface  for  the  axe  in  order  that 
there  will  be  no  appreciable  wear  and  to  reduce  power  consump¬ 
tion  to  the  minimum.  This  design  also  affords  a  simple  and 
excellent  means  for  thorough  lubrication. 

The  axe  is  provided  with  a  first-class  steel  cutting  edge  and 
is  also  carefully  machined  to  fit  the  slides  and  bottom  bearing  as 
above  explained.  By  increasing  the  size  of  the  gears  and  the 
radius  of  the  crank  pin  it  is  possible  to  give^  a  splitter  a  stroke 
of  almost  any  length.  Generally,  however,  this  type  has  a  stroke 
of  15  inches  for  splitting  4-foot  wood. 

There  are  two  crank  gears  on  the  machine.  They  each 
have  thirty-six  teeth,  are  made  of  cast  iron,  and  are  shrouded 
on  both  sides  of  the  teeth.  These  gears  are  driven  by  two  cast 
steel  pinions  each  having  twelve  teeth;  The  pulley,  therefore. 


70  'MODERN  PULP  AND  PAPER  MAKING 

makes  three  times  as  many  revolutions  a  minute  as  is  made  by 
the  crank  gears.  In  other  words,  to  find  the  number  of  strokes 
made  by  a  given  splitter  of  this  type,  multiply  the  r.  p.  m.  of 
the  driving  pulley  by  the  number  of  teeth  in  the  pinions  and 
divide  by  the  . number  of  teeth  in  the  crank  gears. 

The  connecting  rod  is  usuall}^  made  of  cast  steel  and  is  of 
great  strength. 

For  splitting  4-foot  wood  a  40-inch  pulley  is  usually  recom¬ 
mended  as  the  proper  size,  this  to  run  at  a  speed  of  about  no 
r.  p.  m.  If  this  pulley  is  n  inches  in  width  it  is  sufficiently 
large  to  transmit  the  power  through  a  lo-inch  belt. 

Numbers  of  13-FT.  Logs  of^Various  Diameters  in  i  Cord  of  128  Cu.  Ft. 


34  logs  5"  diameter 
27  logs  6"  diameter 
22  logs  7"  diameter 
18  logs  8"  diameter 
17  logs  9"  diameter 
15  logs  10"  diameter 
12  logs  ii”  diameter 

» Courtesy  of  Ryther  &  Pringle  Company. 


10  logs  12"  diameter 
9  logs  13"  diameter 
7  logs  14"  diameter 
6  logs  15”  diameter 
SM  logs  16"  diameter 
5  logs  17"  diameter 


Loose  piled  pulp  wood  in  blocks  24  inches  long  as  dropped 
from  a  Cable  Conveyor  or  loose  piled  in  a  car,  occupies  163 
cubic  feet  for  every  cord  of  128  cubic  feet  close  piled. 

One  cord  of  128  cubic  feet  of  close  piled  rossed  wood  con¬ 
tains  approximately  96  cubic  feet  of  actual  wood. 

A  log  19  inches  diameter  at  butt  and  13  feet  long  equals 

one  market. 

3  Markets  equals  i  Cord. 

5  Markets  equals  1,000  feet  B.  M. 

Average  Adirondack  Spruce  runs  15  to  20  markets  to  the 

3,cr0* 

Hardy  S.  Ferguson,  Consulting  Engineer,  200  Fifth  Avenue. 
New  York  City,  estimates  the  approximate  aniount  of  wood  re¬ 
quired  to  one  ton  of  newspaper  in  the  following  manner. 


Assumptions 

1.  1.08  cords  of  rough  wood  will  yield  I  ton  Air  Dry  Ground 

2.  2  cords  of  rough  wood  will  yield  i  ton  Air  Dry  Sulphite 

3.  In  the  Paper  Mill  2  per  cent,  of  the  Sulphite  is  wasted.  ^ 

4.  In  the  Paper  Mill  8  per  cent,  of  the  Ground  Wood  is 

wasted.  r-  ,  1  •  /  1 

(A)  Paper  containing  25  per  cent.  Sulphite  (neglecting 

fillers). 

_  .  2X23.  1.08X75 _ . 

I  ton  Paper  requires  — ^  +  — —  —  ^  -39  coras. 


THE  SAW  MILL 


71 

(B)  Paper  containing  22^^  per  cent.  Sulphite  (neglecting 
fillers). 

,  -n  •  2X22. t;  1.08X77. ’  , 

I  ton  Paper  requires - ^  =  1.37  cords. 

98  92 

(C)  Paper  containing  20  per  cent.  Sulphite  (neglecting 
fillers). 

,  -n  .  2X20  ,  1.08X80  , 

I  ton  Paper  requires  ■  -  +  ' — —  =:  1.35  cords. 

The  following  Table  taken  from  “The  Woodman’s  Hand¬ 
book,”  published  by  the  U.  S.  Department  of  Agriculture,  gives 
the  volume  of  unpeeled  pulp  wood  in  cubic  feet  of  trees  of  vary¬ 
ing  heights  and  diameters  as  determined  by  measurements  ob¬ 
tained  in  southern  New  Hampshire. 


Height  of  Tree  (Feet) 

Diameter 

breast- 

40 

50 

60 

70 

80 

90 

Basis 

high  ' 

Volume  (Cubic  Feet) 

Inches 

Trees 

5 

1-9 

2.5 

30 

.... 

29 

6 

3-5 

4.2 

5-2 

6.4 

98 

7 

50 

6.2 

7-5 

9.0 

128 

8 

6.6 

8.4 

10. 0 

II. 7 

165 

9 

8.5 

10.8 

12.7 

14.8 

161 

10 

13-5 

15.6 

18.0 

113 

II 

16.5 

18.8 

21.5 

78 

12 

19-5 

22.3 

254 

63 

13 

26.0 

29-5 

34-5 

42 

14 

30.0 

34-0 

39-5 

55 

15 

34-5 

38.5 

44.0 

56 

16 

390 

43-5 

49.0 

49 

17 

43-5 

49  0 

55-0 

63 -5 

38 

18 

48.0 

54-5 

61 .0 

70.0 

44 

19 

530 

60.5 

67-5 

77.0 

30 

20 

58.0 

67.0 

74-5 

83-5 

21 

21 

74.0 

82.0 

90.5 

18 

22 

81.5 

89.0 

98.0 

16 

23 

88.5 

96.5 

106.0 

10 

24 

95-5 

104.5 

114.0 

5 

25 

102.0 

1 12 .0 

123.0 

2 

26 

109.0 

120.0 

131-5 

2 

27 

.... 

128.0 

140.0 

2 

28 

.... 

.... 

.... 

135-5 

148-5 

I 

1,226 

Stumps  varying  from  to  1 feet  and  tops  above  4-inch  diameter  point 
are  excluded. 

To  reduce  to  cords  divide  by  100  or  point  off  two  places.  Some  use  95  cubic 
feet  per  cord. 

Bark  =  1 1  per  cent  of  volume 


V.  The  Wood  Room. 


The  wood  from  the  saw  mill  is  either  carried  directly  on 
conveyors  to  the  wood  room,  or  else  stored  in  large  piles  until 
it  can  be  used.  The  extent  to  which  piles  of  wood  are  accumu¬ 
lated  is  governed  by  a  number  of  factors.  It  is  advisable  to 
use  wood  as  fresh  as  possible,  both  in  the  chemical  and  the  me¬ 
chanical  processes  of  pulp  manufacture  but,  on  account  of_  the 
distance  of  most  mills  from  the  source  of  wood  supply,  it  is 
generally  necessary  to  have  some  wood  stored  in  piles. 


Wood  Piles. 

The  number  of  cords  the  piles  should  contain  and  the  dis¬ 
tance  from  the  mill  buildings,  or  from  each  other,  if  insurance  on 
the  property  is  to  be  obtained  at  minimum  rates,  depends  on  the 
rulings  of  the  insurance  companies.  Disregard  of  these  stipula¬ 
tions  will  cost  many  thousands  of  dollars  each  year  in  the 
case  of  a  large  mill  in  addition  to  presenting  a  constant  menace  of 
fire.  The  value  of  the  wood  in  these  piles  running  into  many 
thousands  of  dollars,  it  pays  well  to  take  every  precaution  again.st 
fire  and  to  have  fire  hydrants  located  conveniently  to  all  the 
piles  of  wood. 

The  wood  should  be  carefully  piled.  Piles  which  lean  out¬ 
ward,  are  irregular  in  shape  and  faulty  in  general  arrangement 
frequently  are  the  cause  of  serious  accidents  to  employees.  In 
freezing  weather  dynamite  is  frequently  used  for  loosening  piles 
of  wood.  This  work  should  only  be  trusted  to  a  careful  and 
experienced  person,  who  should  be  held  responsible  for  the  re¬ 
ceiving,  storage,  handling  and  firing  of  the  explosive.  If  pos¬ 
sible  this  work  should  be  done  at  the  beginning  of  the  working 
day  and  precautions  should  be  taken  to  see  that  all  persons  are 
out  of  the  way  of  possible  danger. 

Wood  Storage. 

The  usual  manner  of  storing  wood  is  to  have  a  conveyor  sup¬ 
ported  on  a  rigid  structure  either  of  wood  or  of  structural  steel. 
This  is  built  as  high  as  may  be  necessary,  in  the  case  of  wooden 
construction  the  height  being  limited  by  the  length  of  timber 
it  is  possible  to  procure  for  the  legs  of  the  structure.  The  higher 
the  structure  the  greater  the  storage  capacity  in  a  given  space. 
Of  course,  the  sfructure  should  not  be  too  high.  This  will  be 
regulated  by  considerations  of  strength  and  of  expense.  The 
wood  is  conveyed  by  a  wire  rope  cable  to  which  are  attached 

72 


THE  WOOD  ROOM 


73 

at  intervals  iron  discs  or  blocks.  The  cable  travels  in  a  wooden 
trough  lined  with  iron  strips.  The  iron  discs  are  so  spaced  as  to 


Courtesy:  Jeffrey  Manufacturing  Co.,  Columbus,  O, 


Fig.  19.— -Wood  storage  conveyor  mounted  on  wooden  trestle  at  large 
mill  in  Newfoundland.  This  installation  will  take  care  of  40,000 
cords  of  wood. 


Courtesy:  hythcr  &■  Pringle  Co.,  Carthage,  N.  V. 

Fig.  20. — Type  of  conveyor  used  for  wood  storage. 

accommodate  2  foot  or  4  foot  blocks  and  to  fit  the  teeth  of  the 
driving  sprockets  at  the  ends  of  the  conveyor.  The  drive  is 
usually  furnished  by  an. electric  motor.  This  motor  should  be 
in  an  accessible  position  and  it  is  wise  to  have  a  hydrant  located 


74 


MODERN  PULP  AND  PAPER  MAKING 


ourtesy:  Jeffrey  Mamifacturing  Co.,  Columbus,  u. 

icr  Wood  Storage  conveyor  showing  how  sections  of  trough  can 

'*■  be  amoved  and  p?Ip  wood  discharged  from  conveyor  to  acconrphsh 
continuous  storage. 


Courtesy:  Jeffrey  Manufacturing  Co.,  Columbus,  O. 

Fig.  22. — Drive  end  of  a  pulp  wood  storage  conveyor. 


THE  WOOD  ROOM  75 

st  this  point,  ES  this  is  one  of  the  most  likely  places  for  fires 
to  start  in  the  wood  storage,  the  motor  being  the  cause.  If  a 
hydrant  is  not  possible  a  good  fire  extinguisher  should  be  kept 
TOnvenient  to  the  motor.  The  motor  should  be  kept  clean  and 
in  good  order  and  inspected  regularly  and  every  precaution  should 
be  taken  against  fires  at  this  point. 

The  wood  is  delivered  to  the  pile  by  the  upper  run  of  the 
conveyor  and  sent  to  the  mill  by  the  lower  or  return  run.  The 
lower  run  is  placed  in  a  trench  or  trough  beneath  the  surface  of 
the  ground  and  this  trench  is  roofed  in  with  heavy  planks  when 


Courtesy:  Jeffrey  Manufacturing  Co.,  Columbus,  0. 

Fig-  23.— Foot  end  of  a  pulp  wood  storage  conveyor  as  installed  at  a 
mill  in  Pennsylvania,  showing  the  method  used  to  maintain  proper 
tension  in  the'  cable. 


the  wood  is  being  stored.  When  the  pile  is  being  depleted  and 
sent  to  the  mill  the  covering  is  removed. 

Another  more  modern  system  of  storage  is  to  have  a  struc¬ 
tural  steel  stacker,  the  base  of  which  rides  on  a  truck  running  on 
rails.  This  stacker  is  built  like  a  section  of  a  cantilever  bridge. 
An  endless  belt  carries  the  wood  up  to  the  tip  of  the  stacker  where 
it  falls  off  onto  the  pile.  The  wood  is  fed  to  the  stacker  from  a 
short  conveyor.  This  scheme  has  the  advantage  that  several 
cars  can  be  unloaded  at  once,  no  long  conveyor  is  necessary  and 
the  track  on  which  the  stacker  moves  can  be  taken  up  and  moved 
along  as  the  pile  develops. 

A  third  system  is  to  have  two  or  more  tall  towers  of  struc¬ 
tural  steel,  concrete  or  wooden  construction,  with  a  conveyor 


76 


MODERN  PULP  AND  PAPER  MAKING 


Columbus,  O 


Courtesy:  Jeffrey  Manufacturing  Co 


Fig.  24.— 


Portable  stacker  and  feeder  conveyor  as  used  for  storing  wood 
from  railroad  cars  at  a  mill  in  Pennsylvama.  • 


Court csy  .*  J cfftcy  LloHufuctm  iiig 


2=;.— Another  view  of  a  portable  pulp  wood  stacker  showing  barked 
wood  stored  and  unbarked  wood  waiting  to  be  barked. 


THE  WOOD  ROOM 


77 


running  between  them.  A  runway  extends  the  length  of  the  con¬ 
veyor  and  wood  can  be  dumped  off  it  at  any  point. 

The  usual  type  of  conveyor  will  handle  250  cords  in  10  hours 
and  requires  H.  P.  per  100  feet  of  conveyor,  travelling  at 
100  feet  per  minute. 

Since  too  dry  wood  is  not  desirable  raw  material  because, 
while  enabling  an  increase  in  production  and  lowering  the  sulphur 
bill'  (because  stronger  acid  is  needed  with  green  wood),  it  de¬ 
creases  the  strength  of  the  paper;  it  is  obvious  that  there  must 
be  a  certain  degree  of  flexibility  in  the  arrangements  for  utilizing 
the  wood.  A  large  mill  storing  from  50,000  to  80,000  cords  of 
wood,  some  of  which  is  rough,  some  peded,  some  fresh  from  the 
forest,  will  have  to  be  so  organized  that  when  a  bad  pile  is  struck 
the  wood  from  it  can  be  gradually  worked  in  with  better  grades; 


Courtesy:  Jeffrey  Manufacturing  Co.,  Columbus,  O. 


Fig.  26. — Wood  storage  conveyor  mounted  on  permanent  steel  towers  at 
plant  in  Quebec.  This  installation  utilizes  a  conveyor  500  feet 
center  to  center  and  takes  care  of  8,000  cords  of  wood. 


Otherwise  the  quality  of  the  paper  would  be  immediately  and 
noticeably  affected. 


The  Work  of  the  Wood  Room. 

The  wood  room  is  a  system  of  machines,  conveyors,  etc., 
for  cleaning  wood,  for  removing  bark  and,  in  those  mills  where 
the  pulp  is  to  be  manufactured  by  a  chemical  process  (sulphite, 
sulphate  or  soda  process)  for  chopping  and  screening  the  wood 
into  designated  sizes  for  the  digesters.  In  the  case  of  mills 
making  ground-wood  or  mechanical  pulp  the  blocks  are  delivered 
direct  to  the  grinders  from  the  wood  room. 

Removing  the  Bark:  It  is  essential  that  every  trace  of  bark 
should  be  removed  from  wood  that  is  to  be  used  for  making  pulp. 
The  bark  colors  the  pulp  and  fills  the  paper  with  dirt  specks. 
Bark  seems  to  hold  its  original  state  unaffected  by  the  chemicals 
used  in  either  the  sulphite  or  the  Kraft  processes  of  pulp  manu¬ 
facture.  It  is  equally  necessary  to  have  the  wood  free  from 
bark  if  it  is  to  be  used  for  ground  wood. 


Fig.  27. — Two  views  of  typical  wood  room  pond. 


In  some  mills  the  bark  is  removed  in  tumbling  drums  and  in 
others  by  means  of  “barkers”  or  barking-machines.  The  latter 
are  less  efficient  both  from  the  standpoint  of  labor  and  waste. 
Tumbling  drums  will  save  sometimes  fifty  per  cent  of  the 
labor  and  ten  per  cent  of  good  wood  which  the  barking-machine 


THE  WOOD  ROOM 


79 


1 


2. 


wastes.  However,  the  first  cost  of  the  equipment  is  much  higher. 

The  two-foot  or  four-foot  blocks  are  delivered  to  the  wood 
room  by  means  of  a  chain  or  cable  conveyor.  This  device 
possesses  the  following  advantages  for  this  purpose; 

It  is  cheaper  than  teams ;  the  blocks  of  wood  may 
be  singly  and  easily  inspected  as  they  pass  a  given 
point  along  the  conveyor ;  two  or  three  different 
qualities  of  wood  may  be  conveniently  mixed  in 
exact  proportions,  as  is  often  desirable  from  neces¬ 
sity  on  account  of  having  a  variety  of  kinds  on  hand 
which  it  is  always  best  to  mix ;  finally,  the  blocks  can 
be  counted  to  determine  the  number  of  cords  used  in 
a  given  time.  The  number  of  two-foot  blocks  con¬ 
tained  in  a  cord  varies  according  to  the  diameter  of 
the  logs  from  which  they  are  cut — ranging  from 
seventy-five  to  one  hundred  and  twenty-five  blocks 
per  cord.  The  average  number  is  gperally  deter¬ 
mined  by  piling  several  cords,  counting  the  blocks 
and  taking  the  average.  This  method,  while  not 
absolutely  correct,  is  a  convenient  way  of  checking 
other  measurements.  All  wood  is  “scaled”  (meas¬ 
ured)  several  times  before  it  is  finally  reduced  to 
pulp.  One  cord  of  green,  peeled  wood  weighs  (ap¬ 
proximately)  3,000  lbs. 

Arriving  at  the  wood  room,  the  wood  is  usually 
dumped  from  the  conveyor  into  a  pond  or  tank  of 
water.  There  is  usually  a  centrifugal  pump  which 
takes  water  out  of  the  lower  end  of  the  tank  and 
delivers  it  to  the  head  end,  thus  causing  a  continuous 
current  which  floats  the  logs  towards  the  tumbling 
drums  or  barking-machines.  There  are  several 
reasons  why  this  floating  process  is  preferable  to 
mechanical  conveyors.  First,  the  maintenance  of  the 
floating  process  is  very  small  compared  with  other 
methods ;  second,  the  wood  in  winter  time  is  freed 
from  ice,  and  the  dirt  attached  to  the  ice,  by  heating 
the  water  with  exhaust  steam ;  third,  all  dirt  adher¬ 
ing  to  the  wood  is  pretty  sure  to  be  removed  during 
its  progress  through  the  pond ;  fourth,  it  serves  as  a 
storage  reservoir  holding  a  surplus  of  wood  so'  that 
there  will  always  be  the  needed  supply  on  hand  for 
the  chippers  or  grinders.  This  pond  is  usually  from 
3  ft.  to  4  ft.  deep,  made  of  pine  or  concrete.  A  pond 
8o  ft.  X  12  ft.  X  4  ft.  deep  requires  21,000  board 
feet  of  lumber.  An  8  inch  slow  speed  centrifugal 
pump,  capacity  600  to  800  g.  p.  m.  requiring  6  H.  P.  ^  ^ 

and  running  at  450  r.  p.  m.  will  provide  for  the  water  circulation. 

Tumbling  Drums:  The  use  of  tumbling  drums  for_  removing 
bark  in  the  paper  industry  was  first  introduced  into  this  country 


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MODERN  PULP  AND  PAPER  MAKING 

by  Bache  Wiig.  His  equipment  took  the  form  of  dosed  cylinders 
of  steel  plate,  into  which  were  packed  four-foot  blocks  parallel 
with  each  other  and  the  sides  of  the  cylinder.  Water  was  in¬ 
jected  through  an  opening  at  the  center  of  the  ends.  When  the 
machine  had  rotated  long  enough  the  logs  were  removed  and 
another  batch  put  in.  The  cylinder  rested  on  trunions.  In  some 
cases  there  was  a  large  girth  gear  by  means  of  which  the  cylinder 
was  rotated. 

These  drums  have  since  given  way  to  drums  made  of  steel 
channel  open  at  each  end  and  operating  continuously,  the  logs 


Fig.  29. — Barking  drum  installation  showing  conveyor  for  removing 

barked  logs. 

being  fed  into  one  end  of  the  slightly  inclined  drums  and  after 
having  all  the  bark  rubbed  off  by  jostling  against  one  another 
and  the  drum,  gradually  working  out  of  the  other  end.  The 
drums  dip  in  a  pond  of  water  which  is  scooped  up  by  the  channel 
irons.  Water  pours  over  the  logs  constantly  while  in  the  drums 
and  washes  away  the  bark,  which  accumulates  in  a  waste  pile  and 
is  generally  burned.  From  the  lower  end  of  the  tumbling  drums 
the  blocks  fall  onto  a  conveyor  which  takes  them  to  the  chippers, 
in  the  case  of  sulphite  mills,  etc.,  or  to  the  grinders  in  the  case 
of  ground-wood  mills.  A  man  is  stationed  at  a  convenient  point 
who  transfers  to  a  conveyor,  leading  back  to  the  pond  in  the  wood 
room  and  back  through  the  drum  for  rebarking,  all  logs  from 
which  the  bark  has  not  been  completely  removed.  The  usual 


Fig.  30. — Barking  drum  showing  driving  and  supporting  chain. 


Fig.  31. — Typical  electric  drive  for  barking  drum. 


81 


82 


MODERN  PULP  AND  PAPER  MAKING 


size  for  these  drums  is  9  to  10  ft.  diameter  by  25  to  30  feet 
long  and  the  capacity  is  12  to  15  cords  per  hour  of  4-foot  wood. 
A  drum  10  ft.  by  30  ft.  requires  about  100  H.  P.  to  drive. 

Barking-Machines :  Although  barking-machines  are  more 
wasteful  of  wood  than  barking  drums,  and  although  it  requires 
more  labor  to  operate  them,  they  are  still  ordinarily  found_  in 
American  mills.  Barkers  sufficient  to  take  care,  of  the  incoming 
of  a  tumbling  drum  installation.  The  first  drum  installations  in 
this  country  were  not  conspicuously  successful  and  the  fact  that 
.improved  equipment  has  removed  the  causes  of  the  early  failures 
has  not  yet  become  as  universally  appreciated  as  might  be  de¬ 
sired. 

A  barking-machine  works  on  the  same  principle  as  a  car¬ 
penter’s  plane.  Four  knives,  analogous  to  the  blades  of  the  plane, 
are  set  in  a  round,  flat-faced  disc.  The  knives  are  set  in  the 
disc  an  equal  distance  apart.  If  a  block  of  wood  is  held  against 
these  revolving  plane-knives  the  wood  or  bark  will  be  shaved 
from  the  block.  Turning  the  block  will  thus  cause  the  bark  to  be 
removed  from  the  entire  circumference. 


Courtesy :  Sandy  Hill  Iron  &  Brass  Works,  Hudson,  Falls,  N.  Y, 

Fig.  31a. — Two  views  of  a  typical  disc  barker. 


Barking  machines  differ  very  little  in  general  construction 
and  style.  A  Barker,  to  produce  good  results,  should  have  a  disc 
at  least  42  inches  in  diameter,  and  should  contain  four  knives. 
The  discs  must  be  in  perfect  balance  so  that  in  revolving  they 
may  run  true,  as  any  extra  weight  on  either  side  causes  an  eccen¬ 
tric  motion  to  the  revolving  disc.  They  are  properly  balanced 


THE  WOOD  ROOM 


83 

before  leaving  the  shop  and  every  reasonable  effort  should  be 
made  to  keep  them  so.  This  is  a  very  important  matter,  as  the 
discs  run  at  a  high  rate  of  speed — from  750  to  950  revolutions 
per  minute,  and  -when  out  of  balance,  cause  the  machine  to  jump 
and  pound,  quickly  destroying  the  bearings,  and  affecting  the 
proper  running  of  the  machine.  It  may  be  said  that  some  discs 
are  run  so  thoroughly  out  of  balance  as  to  be  really  dangerous 
to  life  and  property. 

The  discs  should  be  equipped  with  proper  clearing  irons,  or 
clips,  which  serve  to  keep  bark  and  refuse  from  binding  and 
lodging  between  the  disc  and  shell  or  hood  of  the  barker,  caus¬ 
ing  undue  friction  and  waste  of  power. 

In  a  supply  of  knives  for  these  machines,  there  may  be  some 
which  have  been  worn  considerably  narrower  than  others ;  in 
many  cases  these  knives  of  various  widths  are  put  into  the  same 
barker,  no  attention  being  given  as  to  whether  or  not  the  wide 
knives  are  all  on  the  same  side  of  the  disc.  The  result  is  that 
the  disc  is  thrown  out  of  balance  to  a  dangerous  extent.  If  it 
is  necessary  to  use  various  widths  of  knives,  they  should  be  care¬ 
fully  gauged  or  weighed,  and  heavy  and  light  knives  placed 
opposite  heavy  and  light  ones  respectively,  so  that  the  disc  will  • 
retain  its  proper  balance. 

The  barker  must  be  equipped  with  tight  and  loose  pulleys  so 
as  to  be  stopped  at  will  for  the  purpose  of  re-setting  the  knives. 

Barker  knives  should  be  of  the  best  quality  of  steel,  tempered 
to  stand  hard  usage,  as  wood  is  very  gritty,  containing  many 
hard  and  dry  knots.  They  should  never  be  allowed  to  run  after 
they  become  dulled,  but  should  be  kept  in  proper  condition,  even 
if  it  becomes  necessary  to  change  them  three  or  four  times  a  day. 
They  should  be  ground  with  an  automatic  emery  grinder  with 
water  running  on  them  to  prevent  drawing  the  temper.  Care 
should  be  taken  to  grind  them  in  sets,  all  the  knives  in  a  set 
being  of  the  same  width  and  thickness ;  they  should  be  set  in  the 
grinder  carriage  so  that  the  back  or  blunt  edges  are  lined  up 
against  a  straight  edge,  so  that  in  grinding,  they  shall  be  kept  of 
the  same  width. 

It  very  often  happens  that  barker-men  put  in  a  set  of  knives 
of  various  widths  and  line  up  the  cutting  edges  with  the  emery 
wheel ;  the  first  time  the  carriage  runs  across,  if  the  emery  wheel 
does  not  touch  all  the  knives,  they  are  promptly  rapped  into  line 
with  no  regard  as  to  variations  in  width.  The  result  of  a  con¬ 
tinual  operation  of  this  kind  is  that  there  are  no  two  knives 
of  the  same  width  and  weight  in  the  entire  supply. 

After  removal  from  the  grinder,  the  knives  should  not  be 
placed  in  the  barker  disc  until  finished  with  an  oil-stone  to  re¬ 
move  the  burr  or  wire  edge  left  by  the  emery  wheel. 

Knives  should  always  be  set  by  a  gauge — never  left  to  the 
judgment  of  the  barker-man,  as  it  is  known  to  be  more  laborious 
to  properly  bark  wood  when  the  knives  protrude  but  slightly , 


84  MODERN  PULP  AND  PAPER  MAKING 

while  knives  set  rank  (or  protruding  noticeably),  will  usually 
remove  the  bark  and  considerable  good  wood.  However,  they 
should  be  set  out  not  farther  than  ]/%  of  an  inch  beyond  the 
surface  of  the  disc,  to  avoid  wasting  wood. 

The  shell,  or  casing,  of  the  barker  is  designed  to  carry  off 
the  bark  and  shavings.  The  high  speed  of  the  disc  inside  the 
case  produces  a  blast  similar  to  that  resulting  from  the  use  of  an 
air-blast  fan,  sufficient  to  blow  the  shavings  to  a  considerable 
distance.  Sometimes  small  wings  are  bolted  to  the  disc  to  in¬ 
crease  the  velocity  of  the  shavings.  These  shavings  are  blown 
into  cone-shaped  receptacles,  called  cyclones,  which  are  supposed 
to  give  vent  to  the  air-pressure  made  by  the  revolving  disc,  and 
retard  the  velocity  to  a  speed  suitable  for  the  conveyors.  They 
then  pass,  by  means  of  the  conveyors,  to  the  Boiler  House  for 
fuel. 

The  barker  should  always  be  equipped  with  a  suitable  table, 
adjustable  to  large  and  small  wood.  The  end  of  this  table 
should  always  be  equipped  with  a  stop  to  prevent  the  wood  from 
sliding  endwise  as  the  knives  strike  it;  or,  in  other  words,  to 
counteract  the  force. 

Most  barkers  are  equipped  with  an  automatic  attachment  for 
turning  the  wood.  Some  manufacturers  prefer  not  to  use  this 
attachment,  as  it  is  claimed  to  be  rather  wasteful.  There  is  no 
doubt  that  by  its  use  more  wood  can  be  barked  per  day  than  when 
this  work  is  done  by  hand ;  it  is  a  question  of  figuring  the  loss 
of  wood  against  the  low  production.  Every  effort  should,  of 
course,  be  made  toward  saving  wood. 

A  good  workman  can  bark  approximately  ten  cords  of  wood 
per  day  without  this  attachment,  provided  such  wood  is  of  rea¬ 
sonable  size  and  good  quality — that  is,  does  not  contain  too  many 
gum  seams  and  knots,  the  best  sizes  ranging  from  8  inches  to 
12  inches.  The  wood  should  be  thoroughly  cleaned  of  all  bark, 
gum  and  knots,  to  prevent  the  entry  of  dirt  into  the  pulp  or 
ground  wood. 

Care  must  be  taken  to  protect  employees  against  accidents  on 
these  machines.  The  floor  must  be  kept  free  from  bark  and  never 
allowed  to  become  wet  and  slippery.  Suitable  guards  should  be 
provided  and  there  should  be  ample  room  around  the  barkers. 
All  attachments  must  be  kept  in  proper  repair.  Suit  for  criminal 
negligence  can  be  brought  against  the  superintendent  in  case  of 
accident  to  an  employee  if  it  is  found  that  any  part  of  the  mechan¬ 
ism  was  at  fault,  thus  causing  the  accident. 

The  barkers  must  be  kept  carefully  oiled.  Loose  pulleys  must 
be  oiled.  Special  care  must  be  taken  never  to  allow  the  belt  to 
run  on  the  loose  pulley  any  longer  than  is  absolutely  necessary. 
If,  for  any  reason,  the  supply  of  wood  to  the  barkers  is  stopped 
for  any  length  of  time,  it  is  better  to  shut  off  the  power  than 
to  shift  the  belts  to  the  loose  pulleys. 


THE  WOOD  ROOM 


85 


Chippers. 

Two-foot  or  four-foot  blocks  free  from  bark  are  brought,  by 
a  mechanical  conveyor,  or  by  means  of  another  pond,  from  the 
tumbling  drums  or  barking  machines  to  the  chippers.  These 
are  powerful  machines  which  slice  the  blocks  crosswise  of  the 
grain  into  sections  seven-eighths  of  an  inch  thick,  at  the  rate  of 
eight  hundred  slices  per  minute. 

Before  explaining  the  construction  and  operation  of  this  ma¬ 
chine,  it  might  be  well  to  explain  why  the  blocks  are  not  sawed 
into  sections  of  the  right  thickness.  This  method  has  been  tried, 
but  has  been  found  too  wasteful  and  too  slow.  It  is  wasteful 


Fig.  32. — Chipper  installation  showing  end  of  pond  and  platform  for 

feeding  chipper. 

because  any  saw  suitable  for  this  work  will  make  a  “scarf  (wood 
turned  into  sawdust)  at  least  a  quarter  of  an  inch  wide.  In 
sawing  sixty  thousand  cords  of  wood — a  fair  year’s  supply 
into  sections  seven-eighths  of  an  inch  thick  there  would  be  a  loss 
of  about  14,000  cords  of  wood,  worth  about  $280,000.  More¬ 
over,  the  sawdust  would  be  objectionable  in  the  digesters,  as  will 
be  explained  later.  Wood  for  soda  pulp  is  chipped  a  little 

shorter  than  for  sulphite  or  Kraft.  n  t  a 

The  modern  “Four-Knife  Chipper”  consists  of  a  flat-faced 
disc  of  solid  cast  iron  on  the  rim  of  which  a  steel  ring  is  shiun 
for  safety.  The  disc  is  about  84  inches  in  diameter,  4 
thick  and  weighs  about  3  tons.  It  is  run  at  a  speed  of  fiom  200 
to  225  revolutions  per  minute.  This  disc  is  firmly  keyed  to  a 


86  MODERN  PULP  AND  PAPER  MAKING 

shaft  that  passes  through  its  center.  On  either  end  of  this  shaft 
are  journals  supported  in  journal-bearings.  Keyed  to  this  same 
shaft  is  a  driving-pulley  of  suitable  dimensions,  by  which  the 
disc  is  driven  in  a  vertical  position — similar  to  a  car  wheel. 


Courtesy:  Carthage  Machine  Co.,  Carthage,  N.  Y. 

Fig.  33. — Typical  chipper  with  hood  removed  showing  knives. 


Fig.  34. — Diagram  showing  construction  and  operation  of  standard  chipper. 


The  disc-shaft  and  pulley,  thus  assembled,  are  all  mounted  in 
a  very  substantial  cast-iron  frame,  designed  to  stand  the  violent 
hammering  and  strain.  This  disc,  like  the  barking-machine,  has 
three  or  four  knives  placed  in  a  circle.  The  knives  are  much 
stronger  than  the  knives  on  the  barking-machine  and  are  ground 
at  an  angle  varying  with  the  make  of  the  knife  and  regulated  by 
the  quality  (whether  wet  or  dry,  etc.)  of  the  wood  to  be  chipped. 
By  multiplying  the  revolutions  per  minute  by  the  number  of 


THE  WOOD  ROOM 


87 

blades  (4)  we  arrive  at  the  number  of  cuts  per  minute,  and 
knowing  that  the  chips  are  always  %  inch  thick,  and  knowing 
the  number  of  sticks  to  a  cord  we  can  calculate  the  theoretical 
capacity  of  a  chipper.  Allowance  should  be  made,  of  course,  for 
the  efficiency  of  the  feeding  system, 

Chippers  are  built  in  the  extremely  strong  fashion  explained 
above  on  account  of  the  terrific  violence  of  the  strains  to  which 
they  are  subjected.  The  centrifugal  force  on  the  rim  of  such 
a  disc,  running  at  the  required  number  of  revolutions  per  minute, 
together  with  the  force  with  which  the  knives  strike  a  12-inch 
block  of  sound  spruce  wood  hard  enough  to  cut  a  clean  slice 
seven-eighths  of  an  inch  thick,  across  the  full  diameter,  demands 
the  sturdiest  construction  of  every  portion  of  the  machine. 


Fig-  35- — Cage  type  of  crusher. 


The  spout  of  the  chipper  is  of  cast  iron,  generally  square, 
but  sometimes  round,  and  inclined  at  an  angle  of  forty-five  de¬ 
grees  to  the  disc.  The  reason  for  this  angle  is  to  feed  the  blocks 
against  the  disc  so  that  the  knives  will  strike  in  an  oblique 
manner.  This  may  be  likened  to  whittling  with  a  knife,  which 
is  held  at  an  angle  of  about  forty-five  degrees  instead  of  holding 
it  straight.  Morever,  if  the  chip  is  cut  at  right  angles  the  area 
at  the  end,  and  consequently  the  number  of  pores  exposed,  is  less. 
It  has  been  found  that  the  acid  penetration  in  the  digesters  takes 
place  through  the  ends  of  the  chip,  consequently  it  is  desirable 
to  have  the  end  area  as  large  as  possible. 

At  the  base  of  the  spout  is  a  hardened  steel  bed  plate,  in¬ 
tended  to  prevent  undue  wear  in  the  spout,  and  to  make  the  chip¬ 
per  cut  clean  chips.  This  bed  plate  must  be  renewed  fre¬ 
quently,  If  worn  and  rounded  bed  plates  are  used  they  have 
a  tendency  to  allow  the  wood  in  direct  contact  to  turn  over,  yield- 


88 


MODERN  PULP  AND  PAPER  MAKING 


ing  a  ragged  chip.  A  good  hardened  steel  bed  plate  ought 
to  last  during  the  chipping  of  a  large  number  of  cords  of  spruce 
under  normal  conditions. 

It  is  very  important  that  the  knives  should  be  kept  sharp  and 
in  perfect  condition.  The  chips  must  be 
sliced  off  clean,  without  bruising.  Dull 
knives  will  pinch  off  the  chips,  bruising 
them,  closing  the  pores  and  thus  rendering 
them  impermeable  to  the  acid  when  they 
reach  the  digesters. 

It  is,  of  course,  imperative  that  the  disc 
should  be  run  in  perfect  balance.  With  the 
great  weight  and  high  speed  of  the  disc  it 
will  rapidly  injure  the  journal  bearings, 
which,  apart  from  the  damage  to  the  ma¬ 
chine,  is  very  dangerous. 

Given  proper  attention  and  sufficient 
driving-power  the  chipper  will  handle  from 
8  to  13  cords  of  wood  per  hour.  About  150 
H.  P.  is  usually  required  to  drive  a  standard 
chipper. 

The  chippers  have  an  endwise  adjustment 
controlled  by  a  screw  so  the  disc  can  always 
be  kept  snug  up  against  the  bed  plate.  The 
chippers  discharge  through  a  hopper  into  the 
crusher,  placed  immediately  below. 


\ 


N. 


03 


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Crusher. 

The  crusher  is  a  machine  for  disinte¬ 
grating  the  chips  into  specified  weights  and 
thicknesses  directly  after  passing  through  the 
chipper.  One  type  of  crusher  consists  of  a 
rotor  to  which  are  attached  swinging  pins, 
held  reasonably  positive  by  the  action  of  cen¬ 
trifugal  force.  These  pins  are  held  on  pivots 
of  lignum  vitae  or  oak,  thereby  preventing 
undue  binding  and  protecting  the  fingers, 
which  throw  back  in  case  a  spike  or  bolt  in¬ 
advertently  passes  through  the  crusher,  thus 
saving  the  machine  from  being  wrecked.  The 
pins  should  be  maintained  complete  and  in 
good  condition.  Operating  the  crusher  with 
missing  pins  permits  coarse  chips  and  knots 
to  be  delivered  to  the  belt,  and  while  the 
screens  will  reject  these  to  the  refiner,  the 
efficiency  of  the  whole  installation  will  be 
lowered  on  account  of  the  excessive  amount 
of  waste  of  poorly  prepared  chips,  etc.,  rejected  by  the  screens. 
The  usual  speed  of  the  crusher  is  from  2,000  to  3,000  revolu- 


'O 

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VO 

ro 


THE  WOOD  ROOM 


89 

tions  per  minute.  Another  type  of  crusher  is  designed  on  the 
cage  principle,  as  illustrated. 

Screens. 

The  chips  must  be  screened  very  carefully,  not  only  to  elimi¬ 
nate  large  chips  that  have  failed  to  be  disintegrated  in  the  crusher, 
knots,  etc.,  but  also  to  separate  too  finely  divided  particles,  saw¬ 
dust,  etc. 

Many  theories  have  been  advanced  as  to  the  undesirability  of 
pwdust  in  the  chips.  One  of  these  is  that  sawdust  will  not  cook 
in  the  digesters.  This  has  been  disproved  by  suspending  a 
copper  basket  filled  with  sawdust  in  the  digester.  It  will  cook. 


Courtesy:  Carthage  Machine  Co.,  Carthage,  N.  Y. 


Fig-  37.— Rotary  type  of  chip  screen. 

However,  it  is  very  apt  to  be  overcooked.  In  other  words,  if 
a  Ts  inch  chip  predominates,  it  takes  a  specified  time  for  the 
acid  to  penetrate  and  if  the  digester  contains  95  per  cent  of 
these  inch  chips,  this  95  per  cent  of  the  digester  will  be  prop¬ 
erly  cooked,  and  if  the  other  5  per  cent  consisting  of  sawdust 
will  be  overcooked.  Morever,  any  attempt  to  cook  the  sawdust 
would  result  in  poor  circulation.  There  are  some  conditions 
when  the  digestor  is  first  started  off,  where  the  sawdust  would 
plug  the  strainer.  As  a  result  of  poor  circulation  a  large  part 
of  the  sawdust  might  remain  undercooked  and  appear  in  the 
sheet  as  dirt. 

The  chips  from  the  crushers  are  elevated  to  the  screens  by 
rneans  of  a  scraper  or  drag  conveyor  which  passes  beneath  the 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y. 

Fig.  39. — Standard  type  of  shaker  chip  screen. 

mesh  screen  with  perforations  approximately  i  in.  in  diameter, 
permitting  the  standard  chips  to  fall  through  and  ultimately  go 
to  the  digestor,  and  rejecting  the  balance.  The  chief  objection 


90  MODERN  PULP  AND  PAPER  MAKING 

crusher  and  receives  the  chips  from  the  crusher  through  a  hopper. 
Several  types  of  screens  are  in  use.  The  Lombard,  or  Rotary 


Type,  resembles  a  tumbling  drum.  The  first  section  consists  of  a 
fine  sawdust  section,  removing  all  sawdust  and  particles  smaller 
than  the  standard  chips.  The  second  section  consists  of  a  coarse 


Courtesy:  Mitts  &  Merrill,  Saginaw.  Mich. 

Fig.  38.— Re-chipper. 


THE  WOOD  ROOM 


91 

to  this  type  of  screen  is  that  long  slim  chips  which  should  go 
to  the  re-chipper  stand  on  end  and  go  through. 

Shaker  Screens. 

The  Shaker  Type  Screen  is  preferable  and  works  more  effi¬ 
ciently.  The  shaking  motion  has  a  tendency  to  hold  the  long 
slivers  parallel  to  the  screen  and  sift  them  off.  In  the  rotary 
type  these  slivers  sometimes  get'  stood  on  end  and  fall  through 
the  openings,  thus  finding  their  way  to  the  digester. 

The  Shaker  Screen  consists  of  two  large,  flat  trays,  one 
directly  above  the  other.  The  top  tray  is  covered  with  perforated 
metal  or  wire  with  openings  (about  i  in.  by  in.  in  size), 
which  let  out  the  chips,  but  retain  the  large  knots  and  slivers. 
The  motion  of  the  screen  moves  these  rejected  particles  to  the 
discharge  end,  where  they  fall  into  a  tank  of  water.  The  slivers 
and  large  pieces  of  sound  wood  float  and  are  skimmed  from  the 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N,  Y. 

Fig.  40. — Typical  screening  installation  showing  chipper,  elevator,  and 

chip  screen. 

top  of  the  water  by  a  conveyor  chain,  passing  into  the  re-chipper. 
The  chips  from  the  re-chipper  then  pass  back  to  the  screens. 
The  knots,  being  heavier  than  water,  sink  in  the  tank  and  are 
removed  from  the  bottom  at  intervals.  Knots  are  useless  as 
material  for  pulp. 

The  bottom  tray  of  the  screen  is  covered  with  perforated 
metal  having  openings  only  large  enough  for  sawdust  and  fine 
particles  of  dirt  to  fall  through.  This  waste  is  automatically  con¬ 
veyed  to  the  boiler  house  for  fuel. 

The  standard  sized  chips,  freed  from  those  particles  that  are 
either  too  large  or  too  small,  fall  from  the  screen  to  a  belt  con¬ 
veyor  by  which  they  are  carried  to  the  chip  bins. 


92  MODERN  PULP  AND  PAPER  MAKING 

Re-Chipper. 

This  machine  consists  of  a  disc  or  cylinder  with  sharp  knives 
on  its  periphery.  It  is  not  at  all  like  the  chipper,  being  a  sort 
of  cutter  similar  to  those  used  for  scrap  leather,  etc.  It  requires 
about  2  H.  P.  per  cord  per  hour.  Its  usual  speed  is  from  500 
to  600  r.  p.  m. 

Chip  Bins. 

The  chip  bins  are  large  steel  plate  storage  bins,  the  bottoms 


Fig.  41. — View  in  chipper  department  showing  shaker  screen  with  belt 

and  scraper  conveyors. 

of  which  are  wedge  shaped  to  permit  the  chips  to  flow  freely 
from  the  openings  at  the  base. 

The  chip  bins  are  located  just  above  the  digesters.  The 
opening  at  the  base  is  closed  by  a  sliding  gate  operated  by  a 
hand-wheel.  A  portable  hopper,  suspended  to  rails,  can  be 
placed  to  coincide  with  the  openings  in  the  chip  bins  and  the 
digester-head,  serving  as  a  “funnel”  for  chips  when  filling  the 
digester. 

The  chip  bin  capacity  should  be  so  planned  that  it  will  not 
only  serve  to  accumulate  the  desired  charge  of  the  digesters,  but 
will  also  act  as  a  reservoir  to  take  care  of  the  fluctuation  in  chip 
requirements  and  in  the  chip  production  of  the  wood  room,  It  is 


93 

be  able  to 
g  schedule 


the  wood  room 

customary  to  regulate  the  chip  bin  capacity  so  as  to 
charge  each  digester  every  eight  to  ten  hours  on  runnin 
m  wood  room  of  ten 
hours.  Also  to  enable  the 
digester  to  be  charged 
Sunday  nights  and  the 
cooking  process  started 
without  running  the  wood 
room  overtime.  Condi¬ 
tions  vary,  but  as  a  gen¬ 
eral  rule,  a  cord  of  wood 
when  put  into  chip  form 
will  occupy  from  175  to 
210  cu.  ft. 

Chip  Conveyors. 

The  chip  conveyor 
from  the  chip  screen  in 
the  wood  room  to  the  chip 
loft  is  quite  a  large  piece 
of  conveying  equipment, 
owing  to  the  fact  that  the 
chip  bins  are  located  at 
the  extreme  top  of  the  di¬ 
gester  building,  which  is 
itself  necessarily  a  tall 
structure,  and  the  wood 
room  frequently  has  to  be 
some  distance  away.  In 
many  cases,  this  conveyor 
passes  over  several  other 
buildings  on  a  trestle.  The 
conveyor  is  usually  of  the 
drag  type  with  maple 
flights.  The  width  is  usu¬ 
ally  18  inches  and  the 
spacing  24  inches.  The 
H.  P.  required  to  drive 
this  conveyor  depends  on 
the  layout  and  the  length 
and  pitch  of  the  conveyor. 

A  conveyor  100  feet,  cen¬ 
ter  to  center,  with  25  to 
30  degrees  pitch,  requires 
18  H.  P.  for  a  speed  of 
approximately  125  feet 
per  minute.  The  above 
specifications  give  a  carrying  capacity  of  12  to  15  cords  of 
chips  per  hour.  Sometimes  the  flight  conveyor  does  not  reach 


94 


MODERN  PULP  AND  PAPER  MAKING 


Fig.  43- — External  view  of  Canadian  plant  showing  chip  conveyor  from 

wood  room  to  chip  bins. 

to  the  chip  bins,  discharging  into  a  hopper  at  one  of  the  lower 
floors  of  the  digester  building,  from  which  point  the  chips  are 
elevated  by  a  bootleg  (bucket)  elevator. 

Inspection  of  Chips. 

Chip  tests  are  made  on  this  material  going  to  the  bins  by 
passing  the  chips  through  standard  mesh  sieves,  the  “Ro-Tap  ’ 
machine  being  excellent  for  this  purpose.  Two  analyses  are 
given  below  to  show  how  these  results  may  be  interpreted.  (See 
also  chapter  on  testing.) 


Fraction  Size  Percent 

I  •r\  CJ/-t  it  o  •no  C 


(I) 

Over  yi" 

Square . 

....  18.38 

21.63 

(2) 

to 

Square . 

.  74-77 

54-50 

(3) 

14”  to  3^" 

Square . 

.  5-08 

12-33 

(4) 

Thru  14” 

Square . 

.  1-77 

11-53 

100.00  99-99 


Fraction  i  is  very  coarse,  2  is  good  material,  3  is  irregular 
and  4  is  sawdust.  Test  No.  i,  although  showing  an  abnormal 
amount  of  coarse  stuff,  is  nevertheless  a  very  good  test  while 
No.  2  is  very  poor  for  fractions  one  and  four  are  large  and  two 
is  small.  The  season  of  the  year  affects  the  size  of  chips,  as 
frozen  wood  is  much  more  friable  than  dry  material. 


VI.  Sulphite  Mill. 


In  this  chapter  we  will  consider  the  processes  and  equipment 
required  for  the  manufacture  of  chemical  pulp  by  the  sulphite 
process.  This  includes  not  only  the  actual  equipment  for  the 
sulphite  process,  but  also  the  various  appliances  by  which  the 
pulp  is  washed  and  freed  from  impurities  and  made  ready  for 
use  in  the  paper  mill.  The  acid  plant,  which  is  the  part  of  the 
pulp  mill  devoted  to  preparing  the  acid  liquor  used  in  the  sul¬ 
phite  digesters,  will  not  be  considered  in  this  chapter,  but  will  be 
dealt  with  in  a  separate  chapter  immediately  following  this  one. 


Sulphite  Process.^ 


The  sulphite  process  is  today  the  most  important  method  of 
making  chemical  wood  pulp.  It  was  invented  by  B.  C.  Tilghman 
of  Philadelphia,  who  established  the  process  virtually  as  it  is 
carried  on  today,  although  numerous  chemists  and  engineers  have 
subsequently  made  important  contributions  to  its  theory  and  prac¬ 
tice  which  have  led  to  the  present  efficient  and  valuable  process. 
Tilghman’s  original  patent  was  taken  out  in  1867,  but  it  was  not 
till  considerably  later  that  the  sulphite  process  became  a  real 
working  proposition. 

Tilghman  originally  proposed  digesting  the  wood  in  lead  lined 
iron  cylinders  which  proved  impractical  for  large  scale  operations. 
A  few  years  later  Swedish  engineers  introduced  changes  in  the 
process  that  made  it  commercially  practical,  using  digesters  similar 
to  the  modern  digester,  only  much  smaller,  and  using  an  indirect 
cook,  i.  e.,  not  letting  the  steam  come  immediately  in  contact 
with  the  wood  and  acid,  but  having  the  heat  applied  by  means  of 
a  jacket  and  coils. 

About  ten  years  after  Tilghman’s  patent,  Mitschlerlich  began 
experimenting  with  the  process  in  Germany  and  used  a  digester 
lined  with  brick,  a  form  of  equipment  which  has  since  become 
almost  universally  adopted.  The  original  Mitschlerlich  boilers 
were  from  10  to  12  feet  in  diameter  and  about  36  feet  long.  These 
digesters  were  heated  indirectly  by  means  of  coils  of  lead  covered 
pipe.  The  Mitschlerlich  process  is  still  used  for  certain  classes 


1  It  is  not  the  intention  of  the  author  to  deal  at  great  length  with  the  historical 
development  of  the  sulphite  process,  which,  although  of  great  Interest,  wouW^ 
too  much  space  in  a  book  intended  for.  practical  paper 

the  history  of  the  process  can  be  obtained  in  Griffin  and  Little  s  Chernistry  P 

Making,”  and  also  in  numerous  articles  in  the  various  technical  periodicals 
paper  industry.  But  for  convenience  in  reference  we  have  included  m  this  chapter 
a  copy  of  Tilghman’s  original  patent,  taken  from  Griffin  and  Little. 

Moreover,  no  attempt  has  been  made  to  discuss  in  detail  the  ^®P®hnical 

the  nrocess.  Again  we  must  refer  the  reader  to  Griffin  and  Little  and  to  the  technical 
journals  in  English  and  German  dealing  with  the  paper  induspy,  as  well  as  to  nume 
oTs  articles  tha^t  have  appeared  in  the  publications  of  the  various  chemical  societies. 

Finally  we  have  tried  to  confine  the  discussion  to  types  of  equipment  and  varia¬ 
tions  of  Iheproiell  now  in  actual  use  so  as  to  avoid  confusing  the  practical  reader. 

95 


96  MODERN  PULP  AND  PAPER  MAKING 

of  pulp  and  will  be  described  in  greater  detail  later  in  this  chapter; 
however,  the  apparatus  used  for  the  modern  Mitschlerlich  cook 
has  been  altered  a  good  deal  and  the  digesters  are  larger. 

The  first  practical  working  sulphite  mill  in  America  used  the 
Partington  process,  which  called  for  spherical  digesters  of  the 
rotary  type 

Larger  scale  manufacturing  operations  were  commenced  by 
Wheelwright,  who  overcame  great  difficulties  and  succeeded  in 
producing  pulp  of  excellent  quality  cheaper  than  it  had  ever  been 
made  before.  Wheelwright  devoted  great  attention  to  the  form 
of  the  digester  and  the  nature  of  the  lining  and,  according  to 
Griffin  and  Little,  succeeded  in  reducing  the  cost  of  repairs  on 
linings  from  $10.00  per  ton  of  product  to  about  $1.50  pcr  fo^i 
of  product  in  three  years. 

Tilghman’s  Patent. 

“The  process  of  treating  vegetable  substances  which  contain 
fibres  with  a  solution  of  sulphurous  acid  in  water,  either  with  or 
without  the  addition  of  sulphites  or  other  salts  of  equivalent 
chemical  properties  as  above  explained,  heated  in  a  dost  vessel 
under  pressure,  to  a  temperature  sufficient  to  cause  it  to  dis¬ 
solve  the  intercellular  incrusting  or  cementing  constituents  of 
said  vegetable  substances,  so  as  to  leave  the  undissolved  produce 
in  a  fibrous  state,  suitable  for  the  manufacture  of  paper,  paper- 
pulp,  cellulose,  or  fibres,  or  for  other  purposes,  according  to  the 
nature  of  the  material  employed. 

“I  also  claim  as  new  articles  of  manufacture  the  two  products 
obtained  by  treating  vegetable  substances  which  contain  fibers 
with  a  solution  of  sulphurous  acid  in  water,  either  with  or  without 
the  addition  or  sulphites  or  other  sales  of  equivalent  chemical 
properties  as  above  explained,  heated  in  a  close  vessel,  under 
pressure,  to  a  temperature  sufficient  to  cause  it  to  dissolve  the 
intercellular  or  incrusting  constituents  of  said  vegetable  sub¬ 
stances,  one  of  said  products  being  soluble  in  water,  and  contain¬ 
ing  the  elements  of  the  starchy,  gummy,  and  saline  constituents 
of  the  plants,  and  the  other  product  being  an  insoluble  hbrous 
material,  applicable  to  the  manufacture  of  paper,  cellulose,  or 
fibres,  or  to  other  purposes,  according  to  the  nature  of  the  ma¬ 
terial  employed. 

“I  also  claim  the  use  and  application,  in  the  manufacture  of 
paper,  paper-pulp,  cellulose,  and  fibers,  of  the  fibrous  material 
produced  by  treating  vegetable  substances  which  contain  fibers 
with  a  solution  of  sulphurous  acid  in  water,  either  with  or  without 
the  addition  of  sulphites  or  other  salts  of  equivalent  chemical 
properties  as  above  explained,  heated  in  a  close  vessel,  under  pres¬ 
sure,  to  a  temperature  sufficient  to  cause  it  to  dissolve  the  incrust¬ 
ing  or  intercellular  constituents  of  said  vegetable  substances. 

“I  also  claim  the  use  and  application  of  sulphites  of  other 
sales  of  equivalent  chemical  properties  as  above  explained,  in 


SULPHITE  MILL 


97 


combination  with  a  solution  of  sulphurous  acid  in  water,  as  an 
agent  in  treating  vegetable  substances  which  contain  fibers,  when 
heated  therewith  in  a  close  vessel,  under  pressure,  to  a  tempera¬ 
ture  sufficient  to  cause  said  acid  solution  to  dissolve  the  intercel¬ 
lular  or  incrusting  constituents  of  said  vegetable  substances. 

“I  also  claim  the  recovery  and  re-use  of  sulphurous  acid  and 
sulphite  from  the  acid  liquids  which  have  been  digested  on  the 
vegetable  fibrous  substances,  by  boiling  said  liquids  or  neutraliz¬ 
ing  them  with  hydrate  of  lime.” 

Chemistry  of  the  Sulphite  Process. 

The  following  outline  of  the  chemistry  of  the  sulphite  process 
is  adapted  from  Griffin  and  Little^ : 

“It  is  well  known  that  many  of  the  more  complex  members  of 
the  carbohydrate  group,  to  which  cellulose  belongs,  undergo  more 
or  less  pronounced  changes  upon  being  boiled  with  v/aler,  espe¬ 
cially  if  the  boiling  is  conducted  at  the  higher  temperatures  ob¬ 
tained  under  pressure  in  a  closed  vessel.  Sugar,  which  is  the 
typical  member  of  the  group,  becomes  inverted ;  that  is,  the  sugar 
combines  to  a  limited  extent  with  the  elements  of  water,  and  tlie 
more  complex  molecule  thus  formed  breaks  down  into  the  two 
simple  ones  of  dextrose  and  levulose.  Such  an  action  in  which, 
as  a  result  of  taking  up  the  elements  of  water,  a  molecule  is 
broken  down,  is  called  a  hydrolytic  action,  and  the  decomposition 
itself  is  called  hydrolysis.  Similar  changes  are  brougiit  about 
through  the  action  of  water  alone  upon  cellulose  and  its  incrust¬ 
ing  matters,  but  these  changes  proceed  far  more  rapidly  and  com¬ 
pletely  in  the  presence  of  dilute  acids.  Cellulose  itself  is  com¬ 
paratively  stable  under  these  conditions,  unless  the  temperature 
is  considerably  raised,  but  Lignin,  probably  from  its  greater  com¬ 
plexity,  is  broken  down  with  considerable  rapidity  at  tempera¬ 
tures  not  much  higher  than  that  of  the  boiling-point  of  water. 
The  products  of  the  decomposition  are  largely  organic  acids, 
and  the  direction  of  the  decomposition  is  toward  the  production 
of  these  acids,  but  among  the  earlier  products  there  undoubtedly 
occur  a  considerable  proportion  of  substances  having,  at  least, 
the  general  character  of  the  aldehydes.  When  the  ordinary  min¬ 
eral  acids,  as  sulphuric  or  hydrochloric  acid,  act  in  the  dilute 
form,  and  at  moderately  high  temperatures,  upon  wood,  the  de¬ 
composition  products  rapidly  accumulate  in  the  liquor,  and  un¬ 
dergo  further  secondary  decompositions,  the  course  of  which 
tends  toward  the  production  of  insoluble,  dark-colored,  and  tarry 
matters.  It  is  obviously  impossible  under  these  conditions  to  look 
for  the  production  of  cellulose  in  any  condition  of  purity. 

The  reaction  undoubtedly  takes  a  somewhat  shnilar  course 
when  sulphurous  acid  without  any  base  :s  used ;  indeed,  this  acid 
is  well  known  to  have  a  decomposing  action  upon  many  groups  of 
organic  compounds. 

^  The  Chemistry  of  Paper  Making. 


98  MODERN  PULP  AND  PAPER  MAKING 

The  primary  action  of  a  bisulphite  liquor  in  resolving  wood 
proceeds  upon  the  same  lines  as  that  of  a  solution  of  sulphurous 
acid,  but  the  presence  of  the  base  in  this  combination  rnaterially 
modifies  the  subsequent  course  of  the  reactions.  The  bisulphites 
possess  the  remarkable  property  of  forming,  with  the  aldehydic 
products  of  the  first  stage  of  the  decomposition,  true  double  com¬ 
pounds  which  are  soluble  and  comparatively  stable.  Compounds 
of  this  class  have  been  found  in  the  waste  liquors.  It  is  charac¬ 
teristic  of  the  aldehydes  that  they  pass  by  oxidation  into  organic 
acids,  and  in  spite  of  the  presence  of  sulphurous  acid,  which  tends 
to  prevent  oxidation,  there  is  some  formation  of  these  acids. 
Once  formed,  they  displace  the  sulphurous  acid  from  an  equiva¬ 
lent  portion  of  the  base,  and  form  soluble  organic  salts.  By 
these  two  actions  the  bisulphites  take  up  the  products  of  the  reso¬ 
lution  of  the  wood,  and  prevent  for  the  most  part  the  extreme 
degradation  of  the  products  which  is  characteristic  of  the  water 
treatment  or  of  the  soda  process.  The  combination  of  the  acid 
products  with  the  base  is  shown  by  the  steady  rise  in  the  gas  pres¬ 
sure  observed  during  the  last  part  of  a  sulphite  cook,  and  which 
is  avoided  by  blowing  off.  It  is  also  shown  by  the  composition 
of  the  waste  liquors.  A.  Ihl  finds  that  the  resinous  matter  ob¬ 
tained  by  evaporating  liquors  consists  mainly  of  the  calcium  salts 
of  acids  similar  to  arable  acid,  and  that  these  acids,  as  indicated 
above,  decompose  carbonates,  sulphites,  and  sulphides. 

An  incidental  advantage  of  considerable  importance  is  ob¬ 
tained  by  the  use  of  sulphurous  acid  in  connection  with  a  base, 
and  is  due  to  the  power  of  this  acid  to  form  with  various  coloring- 
matters  compounds  which  are  themselves  colorless.  J  he  piactical 
effect  of  this  latter  action  is  the  production  of  a  fibre  which  may 
be  at  first  of  a  color  as  good  as  that  of  well-bleached  pulp,  al¬ 
though,  as  in  case  of  all  sulphurous  acid  bleaching,  this  high  color 
does  not  persist  for  any  considerable  length  of  time. 

Although  all  the  bisulphites  act  in  general  in  the  manner  speci¬ 
fied  above,  the  character  of  the  liquor  is  modified  in  several  im¬ 
portant  particulars,  according  as  one  base  or  another  is  in  com¬ 
bination  with  the  acid.  Bisulphite  of  lime  is  a  vei*}''  .instable  salt 
which  upon  being  merely  heated  decomposes;  one-half  of  the 
acid  being  set  free.  The  resulting  monosulphite  is  practically 
insoluble,  so  that  when  this  decomposition  occurs  in  the  boiler, 
this  latter  salt  is  precipitated  throughout  the  pulp,  from  which  it 
is  difficult  to  remove  it  by  washing.  When  hme  liquor  is  used, 
there  is  therefore  more  gas  pressure  in  the  digester,  and  the  re¬ 
sulting  pulp  is  comparatively  harsh,  hard  and  transparent.  It  is 
also  more  difficult  to  make  a  straight  lime  liquor  of  high  test  than 
it  is  to  prepare  similar  liquors  from  magnesia  or  soda,  but  on 
account  of  the  insolubility  of  sulphate  of  lime  the  former  liquors 
never  contain  more  than  three-tenths  per  cent  of  sulphuric  acid, 
while  soda  or  magnesia  liquors  may  contain  an  indefinite  amount. 
In  the  case  of  lime  liquors,  any  excess  of  sulphate  over  the 
amount  given  is  precipitated  and  may  be  settled  out. 


SULPHITE  MILL 


99 


Bisulphite  of  magnesia  is  somewhat  more  stable  than  the  cor¬ 
responding  lime  salt,  and  its  action  on  the  incrusting  matter  is 
milder,  but  even  more  effectual.  The  sulphates  or  monosulphites 
which  may  be  present  in  magnesia  liquors  remain  in  solution,  and 
are  easily  washed  out  from  the  pulp.  The  resulting  product  is 
much  softer  and  whiter  than  any  which  is  ordinarily  made  with 
lime  without  some  subsequent  treatment.  I  hese  desirable  quali¬ 
ties  of  magnesia  are  possessed  in  a  still  higher  degree  of  soda. 
Sodium  bisulphite  is  so  permanent  that  it  may  be  easily  obtained 
and  preserved  in  the  crystalline  form.  The  gas  has  so  strong  an 
affinity  for  the  base  that  liquors  of  35°  Be.  may  be  made  without 
difficulty.  Both  the  sulphite  and  sulphate  of  soda  are  very  soluble, 
and  there  is  therefore  no  precipitation  either  in  the  luiqor  appa¬ 
ratus  or  in  the  digester.  Pulp  made  with  soda  liquor  is  white  and 
soft,  and  almost  entirely  free  from  the  last  portions  of  incrusting 
matter. 

It  has  been  held  in  some  quarters  that  sulphuric  acid  in  con¬ 
siderable  amount  is  formed  in  the  digester  during  boiling,  but 
numerous  experiments  show  that  in  reality  this  oxidation  of  the 
sulphurous  acid  is  very  slight-;  it  is  obviously  so  when  we  consider 
that  making  no  allowance  for  the  chips  and  liquor  in  the  digester, 
but  supposing  the  whole  interior  to  be  filled  with  air  at  the 
ordinary  temperature  and  pressure,  the  total  amount  of  oxygen 
contained  therein  only  amounts  to  22  pounds  in  a  digester  of  a 
capacity  of  1,200  cubic  feet,  a  quantity  so  small  when  compaied 
to  the  weight  of  sulphurous  acid  in  the  liquor  that  it  may  be 
disregarded.” 

Digesters. 

The  typical  form  of  digester  used  in  the  sulphite  process  to-day 
is  a  tall  cylindrical  vessel  of  steel  plate  construction  with  a  dome¬ 
shaped  top  and  a  conical  bottom,  as  shown  in  the  drawing.  1  he 
size  of  the  digester  depends  on  the  method  of  cooking  the  wood. 
The  steel  plate  is  usually  %  to  i  ^4  inches  in  thickness.  _  The 
joints  are  triple  riveted.  Several  firms  are  offering  welded  digest¬ 
ers  instead  of  riveted  ones.  These  should  be  good  if  the  welding 
is  well  done,  which  is  a  matter  of  great  difficulty  with  such  huge 
pieces  of  apparatus.  The  welded  digesters  have  hardly  been 
introduced  long  enough  to  say  how  this  development  will  succeed. 

The  riveting  must  be  done  with  the  utmost  care  and  faithful¬ 
ness  and  the  whole  construction  must  be  of  the  strongest  and 
most  thorough  type  on  account  of  the  great  pressure  and  igi 
temperature  prevailing  at  certain  stages  of  the  oppation  e 
outside  of  the  digester  should  be  kept  neatly  painted  and  clean  so 
incipient  defects  can  be  detected  before  they  go  so  far  as  to  be¬ 
come  dangerous.  The  surrounding  building  should  be  wel 
lighted  Windows  and  doors  should  not  be  allowed  to  stand 
open  in  cold  weather  so  as  to  chill  the  sides  of  the  digesters  as 
this  produces  periodical  local  contractions  and  expansions  that 
strain  the  digester,  often  causing  cracks. 


lOO 


MODERN  PULP  AND  PAPER  MAKING 


The  digesters  are  located  in  a  tall  structure  which  supports 
the  chip  bins  over  the  digesters.  The  digesters  rise  through  two 


Fig.  44. — Cross  section  of  digester 
house  showing  chip  conveyor,  chip 
bins,  digester,  blow-pipe,  and  steam 
and  acid  connections. 


floors,  one  being  placed 
just  where  the  cylindrical 
portion  begins  and  the 
other  being  located  so  that 
the  digesters’  heads  just 
rise  through  it.  The  di¬ 
gesters  should  stand  alone, 
no  floors  coming  in  con¬ 
tact  with  them.  The  di¬ 
gester  house  should  be 
strongly  constructed,  well 
illuminated  and  accessible 
at  all  levels  by  good  stair¬ 
ways.  It  should  also  be 
provided  with  a  good  sys¬ 
tem  of  ventilation  to  carry 
off  fumes. 

A  digester  of  the  shape 
described  15  feet  in  diame¬ 
ter  and  49  feet  high  will 
hold  approximately  27 
cords  of  chipped  wood  and 
28,850  gallons  of  acid. 

Essential  Parts  of  the 
Digester : 

1.  Shell. 

2.  Lining. 

3.  Opening  provided 
with  cover  at  top  for  re¬ 
ceiving  chips. 

4.  System  for  filling 
the  digester  with  the  acid. 

5.  System  of  pipes  for 
supplying  the  steam  for 
cooking. 

6.  System  of  relief 
lines  for  getting  rid  of 
steam  and  acid  gas. 

7.  Thermometers  t  o 
record  the  temperature. 

8.  Gauges  for  record¬ 
ing  the  steam  pressure. 

9.  The  blow  valve  and 
blow  pipe  through  which 
the  pulp  is  discharged  un¬ 
der  pressure  when  the  cook 
is  completed. 


SULPHITE  MILL 


lOI 


The  shell  has  already  been  discussed  above.  We  will  now 
pass  on  to  a  discussion  of  digester  linings,  one  of  the  points  which 
gave  the  most  trouble  in  the  early  days  of  the  sulphite  process  and 
which  required  much  patient  experiment  on  the  part  of  Mitscher- 
lich,  Partington,  Wheelwright  and  others.  The  present  method  of 
lining  is  largely  the  result  of  work  by  G.  F.  Russell. 

Lining:  The  acid  used  in  the  sulphite  process  will  rapidly 
disintegrate  naked  iron.  Therefore,  some  kind  of  lining  is  neces¬ 
sary.  Lead  is  chemically  the  material  best  adapted  to  resist  this 
acid,  but  after  years  of  experiment  with  lead  lined  digesters,  they 
have  largely  been  abandoned.  This  is  because  the  coefficient  of 
expansion  of  lead  is  so  different  from  that  of  iron  that  the  two 
metals  will  pull  away  from  each  other  when  subjected  to  altera¬ 
tions  in  temperature.  Lead,  however,  when  once  expanded,  does 
not  contract  to  its  original  shape  and  size  when  the  temperature 
is  lowered  as  do  most  metals.  It  tends  to  remain  in  the  expanded 
form.  This  has  the  result  that  lead  will  “crawl”  or  pull  away 
in  one  direction  from  any  point  where  it  is  held,  thus  making  a 
round  bolt  hole  gradually  into  an  ellipse  and  permitting  leakage. 

We  wiU  not  dwell  on  the  immense  amount  of  ingenuity  that 
was  expended  in  attempts  to  overcome  the  fatal  faults  of  lead 
before  lead  linings  were  finally  given  up  in  favor  of  brick  ones. 
Digesters  built  of  bronze  were  also  tried.  This  bronze,  however, 
did  not  perfectly  resist  the  action  of  the  acid,  as  v/as  proved  by 
chemical  tests,  and  did  not  possess  the  necessary  mechanical 
strength  at  the  temperatures  encountered  in  the  digester.  No 
bronze  has  been  found  that  will  overcome  these  defects.  Numer¬ 
ous  kinds  of  enamels  and  cements  have  also  been  tried.  Al¬ 
though  all  of  these  have  their  advocates,  the  brick  lining  has  come 
to  be  almost  universally  used. 

There  are  generally  two  layers  of  brick,  the  first  separated 
from  the  shell  by  a  i-inch  layer  of  Portland  cement.  The  bricks 
are  laid  with  a  cement  made  as  follows : — one  part  of  sand  or 
crushed  quartz,  and  one  part  of  litharge  are  mixed  dry  and  then 
glycerine  added  to  form  a  thick  paste.  The  glycerine  should  be 
slightly  warmed  before  it  is  used.  Sometimes  a  little  silicate  of 
soda  is  added  to  the  glycerine.  This  helps  the  cement  to  set  well. 
After  the  glycerine  is  added  the  cement  is  kneaded  like  bread 
till  it  is  of  an  even  consistency.  The  glycerine  should  be  added 
to  small  portions  of  the  dry  ingredients  at  a  time,  the  cement 
thus  being  prepared  about  as  fast  as  it  can  be  used.  A  ball  which 
a  man  can  nicely  hold  in  both  hands  will  lay  about  five  bricks. 
Frequently  the  first  layer  of  brick  is  common  red  brick  and  the 
inner  layer  special  vitrified  acid  resisting  brick.  The  two  layers 
are  separated  by  a  thin  layer  of  cement,  either  a  special  cement  or 
ordinary  cement  mortar  mixed  i  to  2.  The  inner  layer  of  vitri¬ 
fied  brick  is  laid  with  great  care  in  the  special  cement  described 
above. 

A  number  of  manufacturers  produce  bricks  specially  adapted 


102  MODERN  PULP  AND  PAPER  MAKING 

to  digester  linings.  In  general  such  bricks  should  be  hard,  homo¬ 
geneous  and  non-absorbent  to  water.  They  should  be  thor 
oughly  baked  and  well  annealed  so  as  to  resist  temperature 
changes.  They  should  be  free  from  iron  and  similar  metals. 
The  best  bricks  will  split  and  crack  to  some  extent  under  the  ac¬ 
tion  of  acid,  temperature  change  and  the  mechanical  agitation  of 
the  liquid,  but  careful  selection  of  brick  can  do  much  to  reduce 
the  quantity  of  such  waste  matter  getting  into  the  pulp  and  also 
delay  the  necessity  of  relining  the  digester. 

When  a  digester  has  been  shut  down  to  be  relined,  or  for  any 


Fig. 


4c —Charging  floor  of  digester  house  showing  digester  heads  and 
acid  and  relief  connections ;  also,  traveling  hopper  for  charging  chips 
into  digester,  with  large  hand  wheel  for  regulating  flow  of  chips. 


other  cause,  or  is  being  started  for  the  first  time,  so  that  it  is  cold, 
it  should  not  be  heated  up  to  a  high  temperature  suddenly.  The 
brick  should  be  allowed  thoroughly  to  dry  out  and  then  the  di¬ 
gester  should  be  gradually  brought  up  to  cooking  temperature. 
The  digester  should  be  at  least  24  to  36  hours  in  warming  up  from 
cold  to  ordinary  cooking  temperature. 

Disregard  of  these  precautions  will  crack  and  disintegrate  the 
brick  lining,  strain  the  shell  and  may  result  in  a  disastrous  ex- 

Insurance  inspectors  should  never  be  misled  and  no  attempt 
should  be  made  to  conceal  anything  from  them.  Their  advice  as 
to  safe  pressures,  repairs,  etc.,  should  be  regarded  as  these  men 


SULPHITE  MILL 


103 


are  selected  for  their  practical  knowledge  and  have  a  wide  experi¬ 
ence  from  inspecting  mills  throughout  the  country. 

Head:  The  “head”  or  cover  of  the  digester  is  removable.  It 
is  fastened  to  a  casting  which  forms  the  top  rim  of  the  digester 
proper  by  means  of  clamps  which  hold  it  securely  in  position 
against  the  internal  pressure  of  the  digester.  The  head  is  lined 
with  a  sheet  of  some  acid-resisting  metal  such  as  aluminum.  Be¬ 
tween  the  head  and  the  rim  on  which  it  sits  is  inserted  a  gasket, 
which  it  has  usually  been  found  economical  and  efficient  to  make 
out  of  a  lap  of  sulphite  pulp. 

A  chain  hoist  is  provided  for  removdng  and  replacing  the  di¬ 
gester  heads,  which  have  to  be  removed  every  time  the  digester 
is  filled  with  chips  and  acid. 

The  head  is  fitted  for  the  connection  to  the  relief  line.  This 
is  usually  a  2^ -inch  bronze  pipe.  It  relieves  the  pressure  in  the 
digester  after  the  steam  has  been  turned  on  and  allows  the  gas 
that  forms  in  the  top  or  neck  of  the  digester  to  escape  to  the  re¬ 
covery  system,  which  will  be  described  later.  After  leaving  the 
digester  this  line  divides  into  two  separate  lines.  One  is  a  liquor 
relief  line  and  one  a  gas  relief  line.  These  lines  are  controlled 
by  valves  and  the  attendant  can  tell  by  the  sound  whether  liquor 
or  gas  is  coming  off  from  the  digester  and  thus  direct  it  into  the 
proper  line.  Both  these  lines  are  of  bronze  and  usually  23/^-inch 
diameter. 

Strainers  should  be  provided  to  prevent  pulp  getting  into  the 
relief  lines,  thus  plugging  them  up.  These  are  usually  hard  lead 
or  bronze  globes  or  hemispheres  provided  with  numerous  holes 
about  3/16  of  an  inch  in  diameter. 

Sieam  Supply:  At  the  base  of  the  digester  are  the  inlets  for 
the  steam.  The  connections  between  the  boilers  and  the  digesters 
should  be  as  short  as  possible  to  prevent  condensation  of  tiie  steam 
and  reduction  of  the  steam  pressure.  Suitable  traps  should  be 
provided  and  all  lines  should  be  covered  with  an  efficient  heat  in¬ 
sulating  substance  such  as  magnesia. 

Where  a  number  of  digesters  are  used,  as  is  usually  the  case, 
the  piping  system  should  be  designed  so  that  all  the  digesters  will 
receive  steam  at  the  same  pressure,  which  will  not  be  the  case 
unless  the  main  line  leading  from  the  boilers  is  adequate  in  size. 

The  steam  pipe  for  the  digester  is  usually  carried  up  to  a  point 
near  the  top  of  the  digester  and  then  down  again,  entering  the 
digester  at  the  bottom.  This  forms  a  trap  which  prevents  any¬ 
thing  being  forced  from  the  digesters  back  into  the  boiler  system 
should  the  steam  pressure  through  any  cause  become  less  than 
the  pressure  in  the  digesters.  This  arrangement  permits  of  the 
reducing  valve  being  located  on  the  working  floor,  i.e.,  the  floor 
where  are  the  digester  heads,  gauges,  etc.,  and  thus  being  under 
the  eye  of  the  operator  at  all  times.  This  line  should  be  pro¬ 
vided  with  one  or  more  suitable  check  valves,  one  in  the  hori¬ 
zontal  section  of  the  pipe  accessible  to  the  working  floor.  The 


104  MODERN  PULP  AND  PAPER  MAKING 

location  of  the  second,  if  such  is  installed,  between  the  first 

check  valve  and  the  digester.  _ 

To  the  bottom  of  the  digester  is  fastened  a  bronze  tee,  the 
side  outlet  being  attached  to  the  digester.  To  one  end  of  the  tee 
the  4-inch  bronze  steam  line  is  connected.  It  is  of  bronze  in  case 


Fig.  46.— Bottom  floor  of  digester  house  showing  conical  base  of  digesters, 

and  blow-pipe. 


any  acid  from  the  digester  should  by  any  chance  get  into  it.  To 
the  other  end  of  the  tee  is  fastened  a  bronze  blow-off  valve  and 
to  this  a  lO-inch  cast  iron  pipe  increasing  in  diameter  to  12  inches 
at  the  farther  end  and  passing  through  the  side  of  the  blow  pit. 


Fig.  47. — Typical. valve  used  for  l)lowing  digester. 

A  digester  such  as  has  been  described  will  require  a  maximum 
of  about  1,200  boiler  H.P.,  the  average  being  about  300  H.P. 
per  hour, 


SULPHITE  MILL 


105 


Cooking. 

There  are  in  general  three  methods  of  cooking  sulphite  pulp. 
The  oldest,  which  is  still  used  for  certain  grades  of  pulp,  is  the 
Mitscherlich  process,  which  is  an  indirect  cook,  the  steam  never 
coming  in  direct  contact  with  the  pulp  and  which  requires  a  spe¬ 
cial  form  of  digester,  which  has  already  been  described.  The 
second  method,  which  is  that  in  general  use,  is  the  Direct  Cook, 
sometimes  known  as  the  Ritter- Kellner  Process  (after  the  men 
who  first  introduced  it  in  Europe)  using  the  vertical  digester  we 
have  already  described.  The  third  method  is  known  as  the  Mor- 
terud  System  and  is  of  recent  invention.  This  is  an  indirect  sys¬ 
tem  with  forced  circulation,  i.e.,  the  acid  is  heated  in  a  heater 
separate  from  the  digester  and  forced  through  the  digester  by 
means  of  a  pump.  All  of  these  methods  have  their  advantages 
and  their  drawbacks. 

Mitscherlich  Process:  The  pulp  produced  by  the  Mitscher¬ 
lich  process  is  of  excellent  quality,  but  the  process  has  been  largely 
abandoned  on  account  of  the  following  disadvantages.  This  is 
a  very  slow  process  to  operate,  the  cooking  time  being  very  long, 
usually  35  to  40  hours  and  in  some  cases  upwards  of  60  hours. 
The  pressure  rarely  exceeds  45  pounds.  The  digester  has  from 
1,000  to  3,000  feet  of  lead  or  copper  pipe  coil  in  it  for  heating 
purposes  which  is  constantly  leaking  and  in  need  of  repair.  When 
the  heating  coils  have  to  be  repaired  the  digester  has  to  be  shut 
down.  On  account  of  leaks,  the  acid  liquor  gets  into  the  con¬ 
densate  from  the  steam  used  for  heating,  thus  making  it  impos¬ 
sible  to  use  this  condensate  in  the  boiler  plant  and  thus  increasing 
the  consumption  of  coal.  Calcium  monosulphite  collects  on  the 
lead  pipes  and  has  to  be  removed  and  will  frequently  drop  into 
the  pulp  during  the  cooking,  where  it  is  very  undesirable.  The 
chips  are  brought  into  direct  contact  with  the  heating  surface, 
frequently  causing  overcooked  pulp  and  lower  yield  from  the 
wood.  On  account  of  uneven  circulation  and  the  fact  that  the 
heating  coils  are  entirely  in  the  lower  part  of  the  digester,  the 
bottom  part  of  the  pulp  will  be  digested  first.  The  pulp  is  not 
blown  out  of  the  digester,  as  in  the  case  with  the  direct  cook,  but 
is  removed  by  shovels  and  rakes  through  a  large  manhole  near 
the  bottom  of  the  digester  after  the  pressure  has  been  relieved. 

In  spite  of  all  drawbacks  the  Mitscherlich  process  is  found 
advisable  in  some  cases.  It  makes  a  very  strong  pulp  ideal  for 
certain  purposes,  which  cannot  be  exactly  imitated  with  a  direct 
cook.  It  is  also  economical  of  sulphur.  A  much  weaker  acid 
can  be  used  than  is  customary  with  the  direct  cook.  However,  it 
will  be  seen  from  the  above  remarks  that  the  process  is  a  very 
troublesome  one. 

Direct  Cooking  Process:  The  first  great  advantage  of  this 
process  is  the  fact  that  it  is  quick,  the  time  varying  in  different 
mills,  but  never  being  anything  like  as  long  as  for  the  Mitscherlich 
process. '  The  second  great  advantage  is  the  comparative  sim- 


io6  MODERN  PULP  AND  PAPER  MAKING 

plicity  of  the  equipment,  leaks  and  other  causes  of  stoppage  being 
cut  down  to  a  minimum  and  repairs  being  as  low  as  possible. 

In  charging  the  digester  it  is  filled  as  completely  as  possible 
with  chips  which,  before  the  cooking  operation  has  proceeded  very 
far,  will  have  settled  enough  to  be  entirely  covered  with  the 
liquor. 

A  digester  15  feet  in  diameter  by  49  feet  high  will  hold  ap¬ 
proximately  27  cords  of  chips  and  requires  about  28,850  gallons 
of  liquor.  Such  a  digester  will  produce  about  12  or  13  tons  air 
dry  pulp. 

The  liquor  should  be  run  in  as  quickly  as  possible.  The  pipe 
for  this  purpose  should  be  at  least  6-inch  and  maybe  larger.  Like 
all  other  connections  with  which  the  acid  comes  in  contact,  it  is 
of  hard  lead  or  bronze.  An  8-inch  centrifugal  pump  of  hard 
bronze  is  satisfactory  for  pumping  the  acid  into  such  a  digester. 
Running  at  approximately  850  r.p.m.  it  will  fill  the  digester  in  25 
minutes.  It  requires’  24  h.p.  against  a  6o-foot  head.  All  connec¬ 
tions  from  the  tank  to  this  pump  and  from_  the  pump  to  the  di¬ 
gester  can  best  be  made  of  hard  lead,  containing  8  per  cent  anti¬ 
mony  in  its  composition.  Modern  mills  are  frequently  designed 
so  that  the  acid  flows  into  the  digester  from  tanks  placed  at  a 
higher  level  than  the  digesters,  thus  obviating  the  use  of  such  a 
pump. 

In  some  mills  the  acid  is  pumped  into  the  bottom  of  the  di¬ 
gester,  a  check  valve  being  inserted  to  prevent  the  acid  running 
back  in  case  of  accident  to  the  pump,  this  valve  being  closed  be¬ 
fore  stopping  the  pump.  In  this  way  the  acid  rises  gradually 
through  the  chips.  This  method  does  away  with  fumes.  How¬ 
ever,  this  method  is  not  to  be  recommended,  as  the  chips  float  and 
do  not  become  thoroughly  saturated  with  acid  and  it  is  hard  to  tell 
when  the  digester  is  full. 

When  the  digester  is  filled  with  chips  and  acid,  the  cover  is 
securely  bolted  on  and  the  pressure  and  temperature  recording 
instruments  noted,  and  at  times  calibrated.  The  relief  valve  is 
slightly  adjusted  to  let  out  the  air.  The  steam  valve  is  then 
opened  and  the  digester  allowed  to  come  gradually  to  65  or  70. 
pounds  pressure.  It  is  very  important  that  the  pressure  should 
not  be  applied  too  suddenly.  The  acid  should  be  allowed  to  thor¬ 
oughly  saturate  the  chips  and  penetrate  every  particle  of  them 
before  any  notable  increase  in  temperature  takes  place.  This  is 
necessary  to  produce  the  proper  chemical  changes  in  the  material 
and  to  prevent  charring  and  overcooking  of  the  chips. 

Moreover,  if  the  heating  is  forced  at  the  beginnmg  of  the 
cook,  the  steam  striking  the  cold  liquid  will  hammer,  which  is  hard 
on  the  digester.  However,  the  chief  reason  for  raising  the  tem¬ 
perature  slowly  is  the  effect  on  the  chips  mentioned  aboye.  If 
reddish  or  brown  bundles  of  fiber  are  found  in  the  pulp  it  is  an 
indication  that  the  pressure  has  been  applied  too  early  before  the 
acid  had  a  chance  to  thoroughly  saturate  the  chips. 


SULPHITE  MILL 


107 

The  pressure  carried  throughout  the  main  portion  of  the  cook 
depends  on  the  grade  of  stock  required,  physical  conditions  of 
the  digester,  maximum  pressure  allowed  by  'the  insurance  com¬ 
panies,  etc. 

In  general  the  temperature  should  not  be  allowed  to  exceed 
110°  C.  until  after  23/^  hours  have  elapsed. 

When  the  steam  pressure  has  been  brought  up  to  standard  the 


Fig.  48. — Temperature  diagram  for  typical  sulphite  cooks.  The  inner 
curve  is  a  pressure  curve  plotted  on  the  temperature  diagram  for 
purposes  of  comparison. 

relief  valves  are  opened  sufficiently  to  shake  up  the  contents  and 
bring  the  acid  up  over  the  top  of  the  chips. 

It  is  impossible  to  give  any  general  directions  for  cooking. 
The  cook  varies  in  every  mill,  depending  on  the  materials  being 
used,  the  grade  of  pulp  being  produced  and  the  personal  ideas  of 
the  man  in  charge  of  operations.  In  some  mills  very  elaborate 
records  are  kept  of  the  temperature  and  pressure  throughout  the 
cooking  operation,  as  well  as  of  the  chemical  composition  of  the 
samples  drawn  ofif  at  various  stages,  and  careful  deductions  are 
made  from  these  facts  and  the  digesters  operated  accordingly.  In 


io8  MODERN  PULP  AND  PAPER  MAKING 

other  mills  rule  of  thumb  methods  prevail  and  the  operation  of 
the  digesters  depends  entirely  on  the  idiosyncrasies  of  some  one 
man. 

The  methods  of  relieving,  in  particular,  vary  greatly,  and  many 
mills  attach  peculiar  importance  to  keeping  their  method  of  per¬ 
forming  this  operation  a  secret.  Many  times  after  the  digester  is 
started,  particularly  within  the  second  and  third  hour  before  the 


Fig.  49. — Pressure  diagram  for  typical  sulphite  cooks. 


final  blowing  time,  the  cook  will  note  a  wet  or  dry  relief,  some¬ 
times  detected  by  the  sound  or  sing  of  the  relief  valve.  With 
proper  cooking  conditions,  the  digester  relieves  100  per  cent  gas 
almost  continuously  for  two  or  three  hours  before  the  end  of  the 
cook.  The  cook  tries  to  hold  the  gas  as  long  as  possible  and  take 
it  all  out  of  the  digester  just  before  the  blowing  point.  He  must 
do  this  as  far  as  possible,  and  yet  not  have  the  temperature  ex¬ 
ceed  the  predetermined  maximum  at  the  time  of  blowing. 

Authorities  vary  as  to  the  proper  temperature.  The  writer 
finds  a  temperature  of  145°  C.  at  the  time  of  blowing  desirable.  ^ 

Certainly  the  temperature  should  not  exceed  149°  C.  and  it  is 
better  to  have  it  somewhat  lower,  especially  if  strong  acid  is  being 


SULPHITE  MILL 


109 

used.  When  weaker  acid  is  used  the  time  of  cooking  has  to  be 
prolonged  also.  In  this  case  the  blow  is  much  darker  in  color. 

For  strong  pulp  which  will  have  a  low  bleach  consumption, 
strong  acid,  a  short  cook  and  a  low  temperature  is  the  proper  com¬ 
bination.  Such’a  cook  produces  high  screenings,  uses  a  great  deal 
of  sulphur,  and  makes  repairs  heavy,  owing  to  the  action  of  the 
strong  acid  on  the  bronze  castings. 

With  weaker  acid  satisfactory  pulp  can  also  be  obtained  with 
lower  percentage  of  screenings,  lower  sulphur  consumption  and 
decreased  repair  cost.  However,  the  cook  must  be  prolonged  and 
the  temperature  maintained  high. 

The  pressure  is  not  an  accurate  indication  of  the  temperature, 
especially  in  the  later  stages  of  the  cook,  as  this  pressure  may  be 
largely  due  to  gas  set  free  by  the  process  proceeding  in  the  di¬ 
gester.  The  temperature  should  be  judged  by  an  accurate  ther¬ 
mometer  placed  about  one-third  of  the  way  down  on  the  digester. 

The  reader  may  wonder,  why,  if  the  grade  of  pulp  to  be  pro¬ 
duced  has  been  settled,  the  strength  of  the  acid,  the  temperature, 
the  pressure  at  every  stage  of  the  cook  and  the  duration  of  the 
cook  cannot  be  absolutely  standardized  and  the  operation  made  to 
conform  to  these  standards.  The  chief  factor  preventing  this  is 
the  wood  which  will  always  vary  in  moisture  content  and  in  other 
regards.  This  variable  factor  makes  it  necessary  for  the  cooking 
operation  to  be  in  charge  of  a  capable  and  experienced  man  who 
can  exercise  judgment. 

However,  much  can  be  done  to  simplify  the  operation  by  mak¬ 
ing  sure  that  the  acid  is  of  constant  strength  and  that  the  con¬ 
densed  water  and  consequent  dilution  of  the  liquor  is  kept  steady 
by  preventing  radiation  as  far  as  possible  and  by  keeping  the 
pressure  of  the  steam  constant. 

Testing. 

During  the  cooking  operation  the  cook  draws  samples  which 
he  analyzes  for  total,  free  and  combined  SO,.  Combined  SO2 
is  that  in  chemical  combination  with  lime  or  lime  and  magnesia, 
free  SO2  is  that  in  solution  in  the  liquid,  total  SO2  is  the  sum  of 
the  two  preceding  amounts. 

The  cook  also  tests  the  smell  of  the  cooking  liquor  and  an 
experienced  man  can  frequently  be  guided  by  this  more  perfectly 
than  by  the  most  extensive  system  of  chemical  control.  The  ap¬ 
pearance  of  the  liquor  is  also  of  importance. 

The  method  usually  employed  for  determining  the  end  of  the 
cook  is  that  of  drawing  off  a  portion  of  the  cooking  liquor  from 
time  to  time  and  determining  the  total,  free  and  combined  SO2, 
smelling  it  and  noting  its  appearance.  Other  means  are  employed 
such  as  blowing  a  small  sample  of  stock  from  the  digester  through 
a  plug  cock  against  a  small  target.  After  examining  this 
a  very  small  portion  of  the  sample  should  be  diluted  in  a  clear 
glass  bottle  filled  with  clear  water.  By  holding  this  up  to  the 


no 


MODERN  PULP  AND  PAPER  MAKING 

light  every  fiber  stands  out  prominently.  If  there  is  any  un¬ 
cooked  wood  these  particles  will  apear  in  a  strong  contrast  to  the 
cooked  fibers.  When  a  digester  has  been  blown  which  meets  all 
the  requirements,  a  sample  of  this  stock  should  be  saved  and 
diluted  in  a  bottle  as  above  for  future  reference.  It  is  surpris¬ 
ing  how  uniform  the  stock  can  be  blown  from  time  to  time  when 
the  operation  is  in  charge  of  an  experienced  cook. 

It  has  not  seemed  to  the  author  desirable  to  take  space  in  this 
book  to  give  details  of  the  chemical  methods  by  which  acid,  liquor 
from  the  digesters,  etc.,  is  analyzed.  Such  details  would  con¬ 
sume  much  space  and  are  of  interest  only  to  the  chemist,  who 
already  knows  where  to  find  such  information.  The  technical 
publications  serving  the  pulp  and  paper  industry  go  into  this  mat¬ 
ter  in  great  detail  and  describe  all  the  standard  methods  which 
have  been  worked  out,  together  with  all  the  various  improvements 
and  criticisms  that  develop  from  time  to  time. 

Morterud  Process. 

The  Morterud  Process  embodies  an  attempt  to  get  away  from 
the  disadvantages  of  the  Mitscherlich  Process,  at  the  same  time 
retaining  the  advantages  of  that  method  of  cooking.  It  is  in  ex¬ 
tensive  use  in  Europe  and  has  been  introduced  with  considerable 
success  into  several  mills  in  America.  Up  to  date  it  has  been 
applied  to  a  greater  extent  in  connection  with  the  sulphate  and 
soda  processes  than  the  sulphite. 

The  system  calls  for  a  specially  constructed  heater  with  bronze 
pipes  in  which  the  acid  is  heated  by  steam  passing  through  the 
pipes.  A  special  circulating  pump  is  used  for  pumping  the  acid 
from  the  heater  into  the  digester.  Another  pump  removes  the 
condensate  from  the  heating  tubes  and  returns  it  to  the  boilers. 
It  is  claimed  that  the  amount  of  acid  required  for  a  cook  by  this 
process  is  30  per  cent  less  than  by  the  direct  cooking  process,  and 
also  that  a  weaker  acid  can  be  used,  on  account  of  the  perfect 
transfusion  of  the  acid  provided  for. 

The  disadvantages,  as  compared  with  direct  cooking,  are; — 
power  is  required  for  operating  pumps ;  the  pumps  and  the  heat¬ 
ing  apparatus  require  repairs;  there  is  a  possibility  of  acid  from 
the  heater  getting  into  the  boiler  system  should  the  heater  tubes 
be  leaking  at  a  time  when  the  pressure  in  the  digester  is  greater 
than  the  steam  pressure  in  the  heater. 

Rotary  Digesters. 

Rotary  digesters  have  been  used  for  the  sulphite  process  and 
are  still  extensively  used  in  Europe.  They  have  the  disadvan¬ 
tages  of  having  to  be  used  in  small  units  for  reasons  of  construc¬ 
tion,  constant  trouble  with  repairs  to  drives  and  steam  connections 
and  numerous  other  minor  disadvantages.  They  secure  uniform 
temperature  and  pulp,  save  fuel  and  use  less  liquor,  and  conse¬ 
quently  can  be  used  successfully  in  countries  where  operations 


SULPHITE  MILL 


III 


are  carried  on  on  a  smaller  scale  and  where  labor  and  construc¬ 
tion  and  repair  charges  are  lower.- 

Blow  Pit. 

When  the  cook  is  finished  the  stock  is  blown  from  the  digester 
through  the  blow  pipe  into  the  blow  pit.  The  blow  pit  is  a  ver- 


Courtesy:  Fibre-Making  Processes,  Inc.,  Chicago,  III. 


Fig.  48. — Sulphite  digesters  arranged  for  indirect  cook  by  Morterud  process 
showing  acid  heater  placed  between  the  two  digesters. 


tical  tank  of  wooden  or  concrete  consttuction  of  sufficient  ca¬ 
pacity  to  hold  two  blows,  i.e.,  twice  the  capacity  of  the  digester. 
It  is  strongly  reinforced  with  iron  hoops,  if  of  wood,  and  has  a 
target  placed  on  the  side  opposite  the  blow  pipe.  This  is  to  pro¬ 
tect  the  tank  from  the  violent  pounding  of  the  stock  as  it  is  blown 
from  the  digester  under  pressure.  The  target  is  usually  of  cast 
iron,  about  i  inch  in  thickness,  and  is  fastened  to  the  tank  with 


II2 


MODERN  PULP  AND  PAPER  MAKING 

heavy  bronze  bolts.  The  blow  pit  has  a  chimney-like  opening  at 
the  top  containing  baffles  to  prevent  any  stock  being  forced  out. 
This  is  called  a  vomit  pipe. 

The  bottom  of  the  blow  pit  is  equipped  with  a  false  or  sec¬ 
ond  bottom.  This  second  bottom  is  usually  of  3-inch  matched 
plank  and  is  set  approximately  6  inches  above  the  actual  tank 
bottom  and  is  provided  with  holes  approximately  i>4  inches 
center  to  center.  These  holes  are  usually  ^-inch  diameter  at 
the  top  and  flare  to  ^-inch  diameter  at  the  bottom. 

Sometimes  this  false  bottom  is  made  of  perforated  vitrified 
brick  tile  set  on  planks  provided  with  large  holes  and  held  in  posi¬ 
tion  by  wooden  fillers  wedged  between  the  tiles. 

The  purpose  of  the  false  bottom  is  to  permit  of  washing  the 
stock  after  it  has  been  blown  into  the  pit.  The  pit  is  filled  with 
fresh  or  white  water  to  a  height  of  two  or  three  feet  on  the  stock. 
Fresh  water  is  preferable  because  white  water  always  contains 
some  acid  and  it  is  necessary  to  wash  all  acid  out  of  the  stock  if 
paper  that  will  not  deteriorate  rapidly  after  being  made  is  to  be 
achieved.  This  water  filters  down  through  the  stock  and  passes 
through  the  perforated  bottom,  carrying  much  of  the  acid  with  it, 
to  the  sewer  or  a  save-all.  This  operation  is  repeated  until  the 
stock  is  washed  free  from  all  acid. 

The  blow  pit  is  fitted  with  a  lead  pipe  connection  at  a  point  just 
above  the  drainer  or  false  bottom.  This  is  usually  8  inches  in 
diameter  and  leads  to  the  pump  used  to  pump  the  stock  from 
the  pit  to  the  intermediate  stock  chest.  This  pump  is  usually  a 
centrifugal  stock  pump.  A  pump  running  at  approximately  1,000 
r.p.m.  will  deliver  the  stock  against  a  head  of  40  feet  with  a 
power  consumption  of  about  25  h.p. 

The  stock  as  it  is  left  in  the  blow  pit  after  washing  is  of  a 
consistency  of  about  12  to  15  per  cent  air  dry,  and  in  order  to  get 
it  out  it  is  necessary  to  use  fresh  or  white  water  to  thin  it  down. 
This  is  done  by  cutting  it  with  a  high  pressure  hose  line.  This 
operation  is  called  hosing  or  sluicing,  and  the  usual  method  is 
to  cut  the  stock  nearest  to  the  suction  line  of  the  pump  and  then 
to  cut  and  hose  towards  that  point.  The  hose  is  usually  a  stand¬ 
ard  2>4-inch  fire  hose  and  should  have  approximately  35  or  40 
pounds  nozzle  pressure  to  obtain  good  results. 

Intermediate  Tanks. 

The  object  of  the  intermediate  tank  is  to  supply  a  storage 
between  the  blow  pit  and  the  screens.  This  tank  should  be  of 
approximately  2  or  3  tons  capacity,  air  dry  stock,  and  should  be 
equipped  with  an  agitator.  Such  tanks  make  sure  of  the  stock 
being  of  a  much  more  uniform  consistency  than  if  it  were  pumped 
direct  from  the  blow  pit  to  the  screens.  The  power  required  to 
drive  the  agitator  is  about  8  h.p.  in  a  tank  15  feet  in  diameter. 

In  making  fine  writing  papers  from  sulphite  frequently  a  num¬ 
ber  of  intermediate  tanks  are  used  in  which  the  stock  is  washed 


SULPHITE  MILL  113 

Systematically,  first  with  white  water  and  finally  with  pure  soft 
water. 

Knotter  Screens. 

The  stock  from  the  intermediate  tank  gravitates  (or  is  pumped 
if  it  is  not  possible  to  arrange  the  equipment  so  it  can  gravitate) 
to  the  knotter  screens.  The  flow  of  stock  is  regulated  by  a  gate 


Courtesy:  Improved  Paper  Machinery  Co.,  Nashua,  N.  H. 

Fig.  49.  Typical  knotter  screen  with  outer  casing  removed  showing 

screen  plates. 

valve.  If  there  is  more  than  one  knotter  screen  there  is  a  header 
and  the  stock  is  distributed  to  each  knotter  screen. 

The  general  type  of  knotter  screen  is  the  rotary  type  which  is 
fitted  with  screen  plates  that  allow  the  good  stock  to  pass  through 
but  reject  the  large  knots  or  lumps  of  uncooked  fibre.  These 


Fig.  50. — Diagram  illustrating  principle  of  knotter  screen. 


knots  and  uncooked  lumps  run  out  of  the  end  of  the  screen,  im¬ 
pelled  by  a  worm  device,  and  are  conveyed  to  a  screenings 
grinder  which  makes  the  minto  pulp  suitable  for  lower  grades  of 
paper,  such  as  mill  wrappers.  While  going  through  the  knotters 
the  pulp  is  showered  with  water  to  wash  off  any  zbres  that  might 
adhere  to  the  knots  or  large  uncooked  lumps.  The  amount  of 


II4  MODERN  PULP  AND  PAPER  MAKING 

water  (which  may  be  either  pure  water  or  white  water)  dilutes 
the  stock  to  approximately  i  per  cent  air  dry. 

The  capacity  of  a  standard  make  of  knotter  screen  is  approxi¬ 
mately  30  tons  per  24  hours  at  a  speed  of  22  r.p.m.  and  with  a 
power  consumption  of  approximately  2  h.p.  The  pressure  on 
the  shower  pipe  of  the  knotter  screen  should  be  from  15  to  20 
pounds,  preferably  the  latter. 

Riffler. 

The  stock  in  passing  from  the  knotter  screen  to  the  next  set 
of  screens  (which  are  either  centrifugal  or  diaphragm  screens) 


Pig_  51 —Discharge  end  of  riffler  showing  pump. 

passes  through  what  is  called  a  riffler.  This  is  a  shallow  wooden 
sluice  about  6  or  8  feet  wide,  equipped  with  a  set  of  baffles  all 
along  the  bottom.  The  riffler  is  on  a  level,  without  any  incline, 
so  that  the  current  is  leisurely,  being  produced  by  the  pump  that 
draws  the  stock  from  the  riffler.  In  this  device  the  various  im¬ 
purities  that  may  be  in  the  stock  sink  to  the  bottom  and  are  held 
by  the  baffles.  The  riffler  should  be  about  18  inches  deep  and  the 
baffles  about  8  inches  high  and  8  or  9  inches  from  each  other. 
The  capacity  of  the  riffler  should  be  sufficient  to  take  care  of  the 
output  of  the  digesters  and  the  length  is  governed  chiefly  by  the 
amount  of  space  able  to  be  devoted  to  it,  the  longer  the  better. 

The  stock  from  the  riffler  is  either  pumped  or  gravitates  to  the 
screens.  If  it  is  pumped  a  centrifugal  pump  with  wide  impellers 


Courtesy :  Baker  Manufacturing  Corporation, 

Fig.  52. — Centrifugal  screen 


Saratoga  Springs,  N.  Y. 
showing  screen  plates. 


115 


Courtesy :  Baker  Alanufacturing  Corporation,  Saratoga  Springs,  N.  Y. 

Fig-  53- — Centrifugal  screen  with  screen  plates  removed  showing  impeller. 

Ii6 


SULPHITE  MILL 


117 

specially  designed  for  handling  stock  is  generally  used.  For  a 
lOO-ton  mill  a  12-inch  slow  speed  pump  of  the  above  kind  will 
serve  very  well  and  will  lift  the  stock  from  40  to  50  feet,  which  is 
generally  sufficient. 

Screens. 

The  screens  may  be  either  centrifugal  screens  or  diaphragm 
screens.  For  fine  papers,  such  as  book  and  writing,  diaphragm 
screens  are  preferable.  For  papers  such  as  wrappings,  bag  pa¬ 
pers,  newsprint,  etc.,  centrifugal  screens  are  quite  satisfactory 
and  their  upkeep  is  much  less  troublesome  and  expensive. 


Courtesy:  H.  L.  Orrman,  Dayton,  O. 

Fig.  54. — Vertical  cross  section  showing  construction  and  operation  of 

Ruth  centrifugal  screen. 

The  diaphragm  screen  is  the  same  type  of  screen  as  is  de¬ 
scribed  in  connection  with  the  Fourdrinier  machine  in  the  chapter 
on  the  machine  room.  For  details  regarding  their  construction, 
operation  and  upkeep  the  reader  should  refer  to  that  chapter. 

The  centrifugal  screen  consists  of  a  runner  or  impeller  sur¬ 
rounded  by  a  cylindrical  screen  plate,  this  in  turn  being  surrounded 
by  a  steel  plate  shell.  The  stock  is  urged  against  the  screen  plate 
through  ports  by  the  centrifugal  force  of  the  runner  and  the  good 
stock  passes  through.  The  rejected  stock  passes  out  the  base  of 
the  screen  and  goes  to  a  secondary  screen  which  is  of  the  same 
construction,  only  coarser.  The  good  stock  from  the  secondary 
screen  is  usually  put  back  through  the  system  and  goes  again 
through  the  primary  screen.  The  rejected  stock  from  the  sec- 


ii8  MODERN  PULP  AND  PAPER  MAKING 

ondary  screen  goes  to  the  screenings  chest.  Another  type  of 
screen  operates  on  the  same  principle  but  is  of  a  horizontal 
design. 

The  entire  battery  of  screens  is  supplied  by  a  canal-like  head 
box,  with  gates  opposite  each  screen  intake  so  that  the  flow  to  the 
screens  can  be  regulated  and  any  particular  screen  can  be  cut  out 
at  any  time.  In  order  to  have  the  stock  supply  to  the  screens  at 
a  constant  head  there  is  an  overflow  from  the  head  of  the  canal¬ 
like  head  box  controlled  by  an  adjustable  dam.  The  overflow 
leads  hack  to  the  riffler  pump  by  a  return  pipe.  The  stock  in 


Courtesy:  Improved  Paper  Machinery  Co.,  Nashua,  N.  H. 

Fig-  55- — Horizontal  type  of  centrifugal  screen. 

the  screen  head  box  is  diluted  with  pure  water  to  a  consistency  of 
about  .5  per  cent  air  dry. 

The  usual  type  of  centrifugal  screen  runs  at  about  400  r.p.m. 
and  has  a  power  consumption  of  approximately  35  h.p. 

Centrifugal  screens  are  kept  clean  by  means  of  a  specially  de¬ 
signed  portable  shower  on  the  end  of  a  hose  which  can  be  inserted 
between  the  screen  plates  and  the  outer  shell.  The  pressure  on 
this  shower  should  be  not  less  than  30  pounds,  as  keeping  the 
screen  plates  clean  is  a  very  important  factor  in  operating  cen¬ 
trifugal  screens.  The  size  of  the  screen  plate  openings  may 
vary  from  55/1000  to  loo/iooo  inch,  depending  on  the  grade  of 
stock  being  screened. 

The  rejected  stock  from  the  knotter  screens  gravitates,  if  pos- 


SULPHITE  MILL 


119 

sible,  to  a  screenings  or  tailings  chest  from  which  it  is  pumped 
with  a  6-inch  fan  pump  to  the  screenings  grinder.  The  power 
required  to  pump  the  screenings  from  a  battery  of  screens  in  a 
lOO-ton  mill  making  sulphite,  with  a  good  arrangement  of  pumps 
and  grinders,  would  be  approximately  15  h.p. 

The  screenings  grinder  used  is  very  often  an  old  Jordan,  al¬ 
though  a  number  of  special  screenings  grinders  are  on  the  mar¬ 
ket.  However,  the  Jordan  is  generally  satisfactory,  especially 
when  the  stock  is  delivered  to  it  with  the  pump  pressure  as  in  the 
layout  described.  The  action  of  the  acid  in  the  stock  on  the  Jor- 


Courtesy:  H.  L.  Orrtnan,  Dayton,  O. 

Fig.  56. — Cross  section  of  Westbye  horizontal  centrifugal  screen.  The 
pulp  enters  the  cylindrical  chambers  “C”  through  inlet  “P”.  From 
“C”  the  pulp  is  discharged  horizontally  through  openings  “E”  to 
runner  “P'”  and  is  thrown  against  the  screen  plates.  The  wings  of 
the  runner  form  a  screw  line  and  the  tailings  are  thus  gradually 
discharged  to  “H”,  where  they  are  washed  out  through  tailings  outlet 
“K.”  Water  under  pressure  enters  “L”  and  is  discharged  through 
holes  “N”  to  the  runner  wings  and  thrown  against  the  screen  plates 
diluting  the  tailings,  while  water  discharged  through  holes  “O”  washes 
out  the  tailings.  The  good  pulp  drawn  through  the  screen  plates 
into  “S”  flows  to  the  bottom  and  is  discharged  from  the  screen 
through  outlet  “T.” 

dan  knives  wears  them  away  very  fast  and  care  should  be  taken 
to  keep  them  in  good  shape. 

From  the  screenings  Jordan  the  stock  is  pumped  with  a  fan 
pump  to  a  screenings  chest,  into  which  the  rejected  stock  from  the 
stock  screens  is  also  run.  From  this  chest  the  screenings  presses, 
which  are  simply  wet  machines  devoted  to  this  particular  duty, 
forms  the  stock  into  laps. 

Deckers  and  Pulp  Thickeners. 

The  good  stock  from  the  screens  gravitates  either  into  the  vats 
of  the  wet  machines,  which  form  it  into  laps,  or  to  the  decker 


120 


MODERN  PULP  AND  PAPER  MAKING 


Fig-  57- — View  in  screen  department  of  sulphite  mill  showing  methods  of 

installing  centrifugal  screens. 


Fig.  58. — Pulp  thickener  installation  in  sulphite  mill. 


SULPHITE  MILL 


I2I 


which  thickens  it  enough  that  it  can  be  used  directly  in  the 
beaters. 

The  reader  may  wonder  why  the  stock  is  formed  into  laps  at 
all  when  these  laps  have  later  to  be  broken  up  and  mixed  with  wa¬ 
ter  in  the  beater.  In  other  words,  it  may  seem  strange  that  all 
the  stock  is  not  simply  run  through  deckers  and  then  to  the  beat¬ 
ers.  This  latter  plan  is  not  practicable  because  frequently  the 
sulphite  mill  is  making  much  more  pulp  than  can  at  that  time  be 
used  in  the  paper  mill.  Every  mill  must  carry  a  storage  and  laps 
are  the  most  convenient  form  in  which  to  store  pulp.  Moreover, 


Courtesy:  Improved  Paper  Machinery  Co.,  Nashua,  N.  H. 

Fig-  59- — Decker  showing  cylinder  and  doctor. 

many  mills  sell  pulp  as  such  to  other  paper  manufacturers  and 
laps  are  the  form  in  which  pulp  is  shipped. 

However,  it  is  good  practice  to  run  as  much  stock  as  possible 
from  the  screens  to  the  deckers,  in  this  way  eliminating  the  power 
required  for  pressing  this  portion  of  the  stock,  as  well  as  the  labor 
and  upkeep  on  the  presses  that  would  be  needed  to  handle  it. 

Various  forms  of  pulp  thickeners  are  used,  of  which  the 
decker  is  the  most  usual.  The  object  of  all  these  machines  is  to 
reduce  the  water  in  the  stock  to  a  certain  predetermined  per¬ 
centage. 

The  decker  consists  of  a  cylinder  revolving  in  a  vat  of  stock. 
The  cylinder  is  first  covered  with  a  foundation  wire  (usually  14 
wires  to  the  inch)  over  which  the  finer  outside  wire  is  stretched. 
This  outside  wire  is  from  50  to  60  mesh  and  against  it  the  pulp  is 


122  MODERN  PULP  AND  PAPER  MAKING 

drawn  by  the  suction.  Wire  as  coarse  as  40-mesh  can  be  used 
if  the  save-all  equipment  is  sufficient  to  catch  all  the  fibre 
through  by  this  coarser  wire.  On  top  of  the  cylinder  is  a  couch 
roll  covered  with  felt  jacketing  or  soft  rubber  Again^st  this 
couch  roll  a  doctor  blade  presses  at  such  an  angle  that  the  pu  p 
slides  off  it  continuously  and  down  into  the  stock  chest  at  which 
stag-e  it  is  referred  to  as  deckered  stock.  _  _ 

Another  form  of  pulp  thickener  consists  of. a  wire-covered 
drum  against  which  the  stock  is  drawn  by  vacuum.  A  mechan¬ 
ical  arrangement  shuts  off  the  vacuum  and  applies  pressure  as  the 
drum  emerges  from  the  vat  of  stock  in  which  it  rotates.  In  t  is 
manner  the  pulp  is  blown  off  the  drum  instead  of  being  scraped 


Courtesy:  Moore  &  White  Co.,  Philadelphia,  Pa. 

Fig.  60.— Horizontal  screen  type  of  pulp  thickener. 


off  by  a  doctor.  It  is  claimed  for  these  machines  that  Hiey  give  a 
greatly  increased  production  together  with  a  higher  efficiency  o 
water  extraction,  which  is  no  doubt  true,  but  the  first  cost  is 
greater  and  the  power  required  also  greater  on  account  of  the 
vacuum  pump  required.  (An  illustration  of  this  machine  will 
be  found  on  page  354  under  “save-alls.  )  _  , 

The  deckered  stock  chest  should  be  equipped  with  an  agitato 
running  at  a  speed  of  approximately  8  r.p.m.  m  order  to  prevent 
settling  and  keep  the  stock  of  constant  consistency  until  delivered 

The  pipe  line  from  the  deckered  stock  chest  to  the  beaters 
should  fo^rm  a  loop,  i.  e.,  the  pump  should  be  running  and  pump¬ 
ing  stock  all  the  time,  returning  the  stock  not  used  m  the  beaters 
back  to  the  deckered  stock  chest.  This  eliminates  the  possibili  y 


SULPHITE  MILL 


123 

of  the  stock  draining  and  plugging  up  the  system.  A  6-inch  fan 
pump  with  a  12-inch  suction  running  at  approximately  800  r.p.m. 
will  furnish  deckered  stock  for  6  beaters  at  a  power  consumption 
of  approximately  15  h.p. 

Wet  Machines,  or  Presses. 

The  wet  machine  is  used  for  that  portion  of  the  stock  pro¬ 
duced  by  the  sulphite  mill  which  cannot  be  deckered  and  used  as 
deckered  stock.  It  is  practically  a  decker  with  a  felt  and  press 
rolls  added.  The  felt  goes  round  the  couch  roll  so  that  it  comes 
in  direct  contact  with  the  film  of  pulp  that  is  picked  up  by  the 
cylinder.  This  film  is  carried  forward  on  the  felt  between  the 
press  rolls  and  allowed  to  wind  around  the  top  press  roll.  When 


if 

Fig.  61.  View  in  sulphite  mill  showing  installation  of  wet  machines. 


it  becomes  thick  enough  it  is  cut  off  with  a  wooden  pm.  The 
size  of  the  sheet  thus  made  is  governed  by  the  circumference  and 
width  of  the  top  press  roll.  This  sheet  is  deposited  on  a  folding 
table  in  front  of  the  press  roll  and  folded  lengthwise  twice  and 
crosswise  three  times,  making  a  sheet  of  pulp  about  18  inches  by 
24  inches.  These  are  called  laps. 

The  machine  is  driven  through  the  bottom  press  roll,  the  felt 
acting  as  a  belt,  driving  the  cylinder  and  the  carrying  rolls. 

Pressure  is  applied  to  the  top  press  roll  by  means  of  a  system 
of  compound  levers  with  weights,  or  by  springs,  or  occasionally 
by  hydraulic  pressure.  Hydraulic  pressure  is  used  chiefly  by 
mills  which^  are  preparing  pulp  for  shipment  to  a  distance,  in 
which  case  it  is  desired  to  eliminate  all  possible  water.  In  such 
cases  the  pressing  on  the  wet  machine  is  frequently  followed  by 
further  pressing  in  a  specially  designed  hydraulic  press. 


124 


MODERN  PULP  AND  PAPER  MAKING 


Coiirtrsv:  Sandv  Hill  Hon  &  Brass  Works.  Hudson  Falls.  N.  Y. 

Fig.  63.-Typical  wet  machine  arranged  for  spring  and  screw  pressure. 


Courtesy:  Improved  Paper  Machinery  Co.,  Nashua.  N.  H. 


64_Wet  machine  arranged  for  liydrauhc  pressure. 


Comparing  levers  with  springs,  the  writer  favors  levers,  he- 

caiise  it?s  possible  to  note  readily  just  how  much 

applied  and  because  it  is  a  check  on  the  wet  machine  tender  with 


125 


SULPHITE  MILL 


reference  to  the  moisture  test  of  the  pulp.  The  levers  and 
weights  are  also  a  more  yielding  system  and  less  likely  to  destroy 
a  felt  m  case  the  layer  of  pulp  becomes  excessively  thick  or  some 
foreign  substance  gets  carried  between  the  press  rolls.  The  lev¬ 
ers  are  more  quickly  disengaged  and  can  be  more  accurately  reset 
exactly  at  the  pressure  previously  exerted. 

The  ordinary  wet  machine,  equipped  with  levers  or  springs 
can  produce  a  pulp  approximately  40  per  cent  dry.  ’ 

_  If  the  rnill  is  equipped  with  efficient  save-alls,  so  that  it  is  cer¬ 
tain  that  all  valuable  fibre  is  caught  in  the  white  water,  wire  as 
coarse  as  40-mesh  can  be  used,  allowing  much  more  rapid  pro¬ 
duction  on  the  wet  machine. 


The  help  in  charge  of  the  wet  machine  should  be  made  to  keep 
the  packings  on  the  ends  of  the  cylinders  perfectly  tight  so  that 
the  stock  does  not  leak  through  and  go  into  the  white  water. 

Should  the  pulp  suddenly  become  full  of  shieves  and  dirt  the 
trouble  can  usually  be  traced  back  to  the  screen  plates  of  the  cen¬ 
trifugal  screens  and  it  will  be  found,  very  likely,  that  a  piece  has 
broken  right  out  of  one  of  these,  or  that  they  have  cracked.  An¬ 
other  cause  of  dirty  pulp  suddenly  appearing  is  a  dirty  vat.  Pulp 
frequently  shows  dirt  from  this  cause  when  a  wet  machine  is 
started  after  having  been  shut  down. 


VII.  The  Acid  Plant 


The  function  of  the  acid  plant  is  to  manufacture  the  solution 

used  to  digest  the  chips  in  the  digesters.  _ 

Numerous  forms  of  equipment  for  manufacturing  this  solu¬ 
tion  have  been  devised,  a  great  deal  of  ingenuity  having  been  de¬ 
voted  to  this  end  since  the  early  days  of  the  sulphite  process. 

It  is  not  our  intention  to  devote  space  here  to  an  account  of 
the  various  systems  that  have  been  tried.  The  reader  will  find 
an  excellent  account  of  the  development  of  such  equipment  in 

Griffin  and  Little.^  ‘  •  ,  i 

We  will,  however,  explain  the  general  principles  of  acid  mak¬ 
ing  and  the  forms  of  equipment  in  general  use  in  America  at  the 
present  time. 

Chemistry  of  the  Process. 

Sulphur,  when  burned,  unites  with  the  oxygen  of  the  air  to 
form  sulphur  dioxide,  SO2,  a  gas  which  dissolves  readily  in  wa¬ 
ter.  There  is  always  a  tendency  for  this  sulphur  dioxide  to  take 
up  more  oxygen,  becoming  oxidized  to  sulphuric  acid.  In  fact, 
this  is  the  way  in  which  commercial  sulphuric  acid  is  manufac¬ 
tured.  In  burning  sulphur  for  the  manufacture  of  sulphite  pulp 
every  precaution  is  taken  to  prevent  the  formation  of  sulphuric 
acid. 

Sulphur  dioxide  in  the  presence  of  water  and  bases,  such  as 
lime  or  magnesia,  forms  solutions  of  lime  or  magnesia  bisulphite. 
If  more  sulphur  dioxide  is  added  than  the  base  will  hold  in  com¬ 
bination,*  it  goes  into  solution  in  the  liquid,  the  amount  depend¬ 
ing  on  the  temperature  and  pressure.  The  diagrams  on  pages 
127  and  128  show  the  solubility  of  sulphur  dioxide  in  water  at 
various  temperatures  and  pressures. 

The  liquid,  generally  called  “acid,”  which  is  used^  in  the  sul¬ 
phite  digesters  consists  of  lime  and  magnesia  bisulphites  in  solu¬ 
tion  together  with  free  sulphur  dioxide  in  solution.  The^  acid 
may  also  contain  some  sulphate  and  some  monosulphite,  but  if  the 
operation  is  properly  conducted  the  amounts  of  these  compounds 
will  be  negligible.  Their  presence  is  very  undesirable. 

This  acid  is  distinctly  corrosive  and  has  to  be  bandied  m  equip¬ 
ment  constructed  of  materials  selected  to  resist  its  corrosive  ac¬ 
tion.  All  pipes,  connections,  valves,  pumps,  etc.,  with  which  it 
comes  in  contact  must  be  of  bronze,  hard  lead  or  some  other  acid 
resisting  material. 

1  The  Chemistry  of  Paper  Making. 


126 


THE  ACID  PLANT 


127 


Raw  Materials. 

Sulphur:  Sulphur  is  one  of  the  chemical  elements,  being  de¬ 
noted  in  chemical  symbolism  by  the  letter  S.  Most  American 
sulphur  comes  from  Louisiana,  where  it  is  obtained  in  a  high  de¬ 
gree  of  purity  from  deep  borings  out  of  which  it  is  expelled  by 
superheated  water,  after  which  it  is  allowed  to  solidify  in  bins. 
It  is  a  hard  yellow  solid  which  is  crushed  and  pulverized  to 

O  fJOLC/S/L/Ty  Of  yy/7T^/?  /7T 

I  CO/VQT/7Ar7-  T^-A//^/E'/?/7TO'/=?EO  Qr 


Courtesy:  "Paper,”  New  York. 

Fig.  64a. 


various  degrees  of  fineness  according  to  the  use  to  which  it  is  to 
be  put. 

Sulphur  should  be  stored  at  the  mill  in  bins,  which  may  be  of 
wood,  concrete  or  metal.  A  number  of  bins  of  moderate  capacity 
is  preferable  to  one  huge  bin  because  it  is  easier  to  inventory  the 
sulphur  periodically  and  also  the  fire  risk  is  less.  The  bins  fre¬ 
quently  have  bands  painted  on  them  indicating  various  tonnages 
of  sulphur  so  that  it  can  readily  be  ascertained  how  much  sulphur 
is  on  hand  at  any  time.  It  is  very  important  that  the  sulphur 
storage  should  be  ample,  and  as  this  material  does  not.deteroriate 
with  keeping,  a  liberal  supply  should  be  maintained  at  all  times. 
The  sulphur  is  weighed  as  it  is  received  at  the  mill  and  again 
when  supplied  to  the  burners.  In  this  way  an  accurate  check  is 
kept  on  the  sulphur  consumption.  Periodical  analyses  of  the  sul¬ 
phur  should  be  made  by  the  laboratory,  to  determine  the  percen- 


128 


MODERN  PULP  AND  PAPER  MAKING 

t 

tage  of  ash  in  the  sulphur  for  the  guidance  of  the  acid  and  di¬ 
gester  departments. 

Limestone:  The  supply  of  limestone  is  usually  obtained  from 
the  nearest  location  to  the  mill  where  it  can  be  economically  quar- 

6oLUB/L/ry  or  Soa  w  in'rrrfT/fT 


Courtesy:  “ Paper,"  New  York. 

Fig.  64b. 


ried.  Dolomite,  or  limestone  with  a  high  magnesia  content,  wa^ 
formerly  preferred  by  mills  making  strong  sulphite  such  as  that 
used  for  bag  and  wrapping  papers,  writing  and  book  papers,  etc. 
However,  nowadays  satisfactory  pulp  of  tins  class  is  being  made 
with  acid  from  limestone  analyzing  97  per  cent  lime  and  no  mag¬ 
nesia  present  at  all.  Newsprint  mills,  the  product  of  which  does 
not  require  strength,  and  which  is  usually  produced  by  a  short 


THE  ACID  PLANT 


129 


cook  with  weak  acid,  prefer  limestone  as  low  as  possible  in  mag¬ 
nesia.  The  reasons  for  the  use  of  dolomite  have  largely  disap¬ 
peared  with  the  substitution  of  towers  for  milk-of-lime  systems. 

Sulphur  Burners. 

Several  different  types  of  sulphur  burner  are  in  use.  The 
older  type,  which  has  largely  been  replaced  by  more  efficient  de- 


Fig.  65. — Installation  of  fiat  type  sulphur  burners. 


vices,  is  the  flat  burner.  These  are  essentially  cast  iron  retorts, 
the  body  consisting  of  a  single  casting.  The  cross  section  is  semi¬ 
circular  or  “D”  shaped.  They  are  usually  about  8  feet  long  and 
2  feet  wide  on  the  outside  and  the  maximum  height  on  the  in¬ 
side  is  about  18  inches.  These  burners  are  set  in  banks  in  a  brick 
setting,  a  sufficient  number  being  installed  to  provide  the  amount 
of  sulphur  dioxide  required  for  making  the  volume  of  acid  needed 
by  the  mill.  The  doors  of  the  burners  are  thus  ranged  in  a  hori¬ 
zontal  row  at  a  convenient  height  from  the  floor  so  that  the  sul¬ 
phur  can  be  chai'ged  into  them  with  shovels.  When  once  ignited, 
the  sulphur  maintains  combustion  if  an  adequate  supply  of  air  is 
admitted  to  the  burner.  This  air  supply  is  regulated  by  dampers 
in  the  doors  and  the  regulation  must  be  attended  to  by  a  careful 
and  experienced  man,  because  if  too  much  air  is  admitted  there  is 
a  tendency  to  form  sulphuric  acid  which  forms  sulphates  in  the 
sulphite  acid  which  are  insoluble  and  cause  trouble  in  the  di¬ 
gester  and  in  the  washing  of  the  pulp.  Moreover,  if  too  much  air 


130  MODERN  PULP  AND  PAPER  MAKING 

is  admitted,  this  excess  air  dilutes  the  gas  produced  in  the  burners 
and  cuts  down  the  efficiency  of  the  tower  system.  On  the  other 
hand,  an  insufficient  supply  of  air  results  in  incomplete  combus¬ 
tion  of  the  sulphur  and  this  causes  sublimation  or  deposit  of  un¬ 
burned  sulphur  throughout  the  system,  which  is  troublesome  and 
cuts  down  the  efficiency.  The  sulphur  dioxide  leaves  the  furnace 
through  the  pipe  which  is  either  bolted  to  the  back  of  the  furnace 
or  else  to  the  top  of  the  arch  near  the  back  end.  ^ 

Owing  to  the  violent  changes  in  temperature  inseparable  from 
the  operation  of  sulphur  burners  of  the  flat  type,  there  is  a  notable 
amount  of  expansion  and  contraction  in  the  burner  itself.  Unless 
some  provision  is  made  to  take  care  of  this  expansion  and  con¬ 
traction,  the  whole  system  of  pipes  leading  from  the  burner  will 
be  badly  distorted.  One  device  that  can  he  introduced  to  lessen 


Courtesy:  Glens  Falls  Machine  Works,  Glens  Falls,  N.  Y, 

Fig.  66. — Rotary  type  of  sulphur  burner. 


this  evil  is  to  place  the  burner  not  directly  upon  the  brick  setting 
but  upon  rollers  which  will  permit  of  a  certain  amount  of  motion 
as  the  burner  expands  and  contracts.  Another  precaution  is  to 
have  the  flanged  joint  between  the  burner  proper  and  the  pipe 
through  which  the  gas  escapes  more  or  less  flexible.  ^  This  can 
easily  be  done  by  pot  having  this  flange  bolted.  In  this  way  the 
two  surfaces  can  slide  on  each  other  with  some  degree  of  freedom. 
Of  course  the  two  surfaces  will  have  to  be  practically  air-tight 
as  otherwise  there  would  be  considerable  leakage  or  infiltration 
of  air. 

A  more  efficient  type  of  sulphur  burner  is  the  rotary  burner 
developed  by  Tromblee  and  Pauli.  This  burner  consists  of  a  cast 
iron  cylinder,  usually  about  8  feet  long  and  about  2  feet  in  diame¬ 
ter  mounted  on  brick  settings  and  revolved  slightly  by  means  of 
'  gears.  At  each  end  of  the  barrel  is  a  cone.  The  rear  cone  con¬ 
nects  with  the  pipe  which  carries  off  the  sulphur  dioxide  and  the 
front  cone  contains  the  damper  by  which  the  air  supply  is  regu¬ 
lated.  The  revolution  of  the  burner  constantly  keeps  a  fresh 


THE  ACID  PLANT  131 

surface  of  sulphur  exposed  to  the  air,  thus  givino  very  efficient 
combustion.'  The  sulphur  is  fed  to  the  burner  from  a  small 
bin  directly  above  the  damper.  A  worm  is  generally  used  to 
facilitate  steady  and  equal  feeding  of  sulphur  to  the  burner. 
The  gases  are  conveyed  from  the  burner  proper  into  a  compara¬ 
tively  large  combustion  chamber,  provided  with  dampers  through 
which  air  can  be  admitted  to  complete  the  combustion  of  the  sul¬ 
phur.  In  case  any  sulphur  becomes  sublimed,  on  account  of  in¬ 
sufficient  air  supply  through  the  front  damper,  it  is  caught  in  this 
chamber  where  combustion  is  completed  and  prevented  from  get¬ 
ting  into  the  cooler  and  the  acid  system. 


Fig.  67. — Exterior  and  cross  section  of  Vesuvius  sulphur  burner. 


Another  type  of  sulphur  burner  is  the  Vesuvius  burner  which 
consists  of  a  cylindrical  steel  shell  lined  with  fire  brick  containing 
a  number  of  shallow  trays.  These  trays  are  so  arranged  that  the 
molten  sulphur  will  drip  down  from  each  tray  to  the  one  below, 
burning  as  it  drips.  The  sulphur  is  placed  in  a  melting  pot  at  the 
top  of  the  burner.  This  melting  pot  has  a  needle-point  valve  in 
the  bottom.  A  fire  is  lighted  in  the  top  tray  and  as  soon  as  the 
sulphur  begins  to  melt  the  needle-point  valve  is  opened  and  the 
sulphur  drops  down  on  to  the  first  tray  beginning  to  burn.  The 
heat  soon  melts  all  the  sulphur  in  the  pot  and  gradually  the  valve 
is  opened  wider  and  wider  and  the  burning  molten  sulphur  drips 
down  from  tray  to  tray  until  it  enters  the  bottom  chamber  where 
the  ashes  and  impurities  collect.  Each  of  the  chambers  is  pro¬ 
vided  with  a  door  fitted  with  a  damper  for  the  admission  of  air. 
From  the  burner  the  gases  pass  to  a  combustion  chamber  wherein 
the  sulphur  fumes  undergo  a  final  combustion.  One  of  the  ad- 


132  MODERN  PULP  AND  PAPER  MAKING 

vantages  of  this  type  of  burner  is  that  it  does  not  require  any 
power  to  operate.  Moreover,  no  hand  firing  is  required.  All 
ashes  or  impurities  called  “slag”  are  automatically  carried  to  the 
bottom  of  the  apparatus  where  they  can  easily  be  removed. 

Coolers. 

From  the  combustion  chamber  the  sulphur  gas  is  led  to  the 
coolers.  It  is  necessary  to  cool  the  gas  to  about  25°  C.  before 
entering  the  towers.  If  the  air  supply  has  not  been  carefully 
regulated  sulphuric  acid  will  be  formed  in  the  coolers.  The  vol¬ 
ume  of  air  required  to  burn  one  pound  of  sulphur  to  15  per  cent 
SOo  gas  is  78  pounds  or  9  cubic  feet.  The  burner  should  be  so 


Fig.  68. — Installation  of  lead  pipe  coolers. 

regulated  that  about  15  per  cent  SO2  gas  is  formed  in  the  burn¬ 
ers.  The  combustion  chamber  should  be  as  large  as  possible  and 
should  contain  baffles  to  collect  the  dust  and  sublimed  sulphur. 

If  the  above  precautions  have  been  observed  and  the  gas  is 
properly  made  it  will  be  cooled  in  the  coolers  without  any  con¬ 
siderable  contamination  with  sulphuric  acid  and  will  also  be  free 
from  sublimed  sulphur. 

There  are  numerous  types  of  coolers  in  use.  One  type  con¬ 
sists  of  a  system  of  lead  pipes  flanged  to  lead  headers.  The  gas 
enters  at  one  end  of  the  header  and  passes  through  the  pipes  and 
out  through  the  header  at  the  other  end.  This  whole  system  of 
pipes  is  contained  in  a  vat  or  pond  and  the  water  supply  is  ar¬ 
ranged  so  that  the  water  enters  at  the  end  opposite  to  the  gas 
entrance.  In  some  cases  the  system  of  pipes  is  only  partially  im¬ 
mersed  in  water  and  is  showered  with  water  from  sprays.  This 
is  much  better  practice  than  merely  depending  on  the  water  in 
the  tank  to  cool  the  pipes.  On  account  of  poor  circulation  the 
water  nearest  to  the  pipes  will  become  heated  and  remain  so  and 
the  maximum  cooling  effect  will  not  be  obtained,  whereas  with 
the  spray  system  fresh  water  is  constantly  dripping  over  the 
pipes  and  is  also  being  cooled  by  evaporation  owing  to  the  finely 


THE  ACID  PLANT 


133 

divided  water  being  constantly  brought  in  contact  with  the  air. 
A  very  efficient  form  of  cooler  is  the  Sandberg  cooler  furnished 
with  the  Jenssen  acid  system.  This  cooler  consists  of  a  header 
and  a  series  of  lead  pipes  placed  in  a  concrete  tank  filled  with  wa¬ 
ter.  The  gas  enters  the  header  and  passes  through  the  pipes 
which  stand  horizontally  and  are  connected  at  the  top  by  U  bends. 
Water  is  sprayed  into  the  top  of  the  cooler  and  flows  down  the 


Courtesy:  G.  D.  Jenssen  Co.,  New  York. 

Fig.  69. — Diagram  showing  the  construction  of  Sandberg  cooler. 


pipes  and  out  through  the  concrete  tank  into  the  sewer  or  for 
further  utilization.  If  the  lead  pipes  are  kept  in  a  good  state  of 
repair,  this  water  will  be  perfectly  pure  and  can  be  used  for  wash¬ 
ing  purposes  or  as  boiler  feed  water,  thus  utilizing  the  heat  given 
up  by  the  sulphur  gas.  This  type  of  cooler  is  not  only  very  effi¬ 
cient  but  is  easily  cleaned  as  the  top  of  the  cooler  is  readily  acces¬ 
sible  and  the  U  bends  can  be  taken  off  and  the  entire  system  of 
tubes  cleaned  whenever  necessary. 

The  cooler  should  be  as  near  the  combustion  chamber  as  pos¬ 
sible  so  that  the  cooling  of  the  gas  will  be  rapid.  Slow  cooling 


134  MODERN  PULP  AND  PAPER  MAKING 

tends  to  produce  sulphuric  acid.  This  is  on  account  of  the  fact 
that  the  best  temperature  for  the  formation  of  sulphuric  acid  is 
from  200°  C.  to  900°  C.,and  on  this  account  the  gas  should  be  pro¬ 
duced  as  at  high  a  temperature  as  possible  in  the  sulphur  burner, 
and  then  cooled  as  rapidly  as  possible  in  the  coolers,  so  that  there 
is  never  at  any  time  any  considerable  volume  of  gas  within  the 
range  of  temperature  favorable  to  the  production  of  sulphuric 
acid. 

Absorption  Equipment. 

There  are  two  chief  classes  of  equipment  in  which  the  sulphur 
dioxide  gas  is  brought  into  contact  with  the  lime  and  thus  con¬ 
verted  into  acid  for  use  in  the  digester. 

One  form  of  equipment  is  generally  known  as  the  milk-of- 
lime  system.  In  this  system  the  gas  is  brought  into  contact  with 
water  containing  the  lime  in  suspension.  The  second  and  more 
modern  system  of  acid  making  is  known  as  the  tower  system. 
In  this  system  the  gas  is  brought  into  contact  with  limestone,  not 
lime,  in  the  presence  of  water. 

In  the  milk-of-lime  systems  the  gas  first  dissolves  in  the  water 
and  the  solution  immediately  reacts  with  the  lime  to  form  mono¬ 
sulphite  which  is  quite  insoluble  and  separates  from  the  solution. 
The  formation  of  monosulphite  goes  on  in  the  tank  until  all  of 
the  lime  is  precipitated  in  this  form.  As  the  addition  of  gas  con¬ 
tinues,  the  monosulphite  gradually  takes  up  more  sulphur  dioxide 
gas  forming  bisulphite  which,  unlike  the  monosulphite,  is  readily 
soluble  in  water.  Unfortunately  sulphur  dioxide  gas  in  solution 
tends  to  form  sulphuric  acid  and  in  practice  there  is  always 
formed,  together  with  the  bisulphite,  more  or  less  sulphate  which 
is  insoluble  and  remains  in  the  acid  as  a  white  precipitate,  com¬ 
monly  called  “gypsum.”  This  precipitate  gives  a  great  deal  of 
trouble  in  the  acid  and  in  the  digesters.  Although  it  is  generally 
regarded  as  insoluble,  it  is  not  absolutely  so  and  a  sufficient 
amount  of  it  dissolved  in  the  acid  afterwards  separates  out  in  the 
digester,  where  it  frequently  plugs  up  in  the  bottom  connections 
of  the  digester  causing  trouble  when  the  digester  is  to  be  blown. 
The  removal  of  this  gypsum  is  a  matter  of  great  difficulty,  as 
when  it  is  allowed  to  accumulate  it  has  to  be  chipped  out  with  a 
hammer  and  chisel.  This  is  troublesome  and  expensive  and  in¬ 
volves  shutting  down  the  digester,  and  also  is  hard  on  the  lining. 
Sometimes  the  gypsum  will  close  up  the  outlet  from  the  digester 
to  such  an  extent  as  to  make  it  very  slow  and  difficult  to  blow  out 
the  stock. .  From  the  above  considerations  it  will  be  realized  that 
every  precaution  should  be  taken  to  prevent  the  formation  of  sul¬ 
phate  or  gypsum  in  the  acid.  This  can  only  be  guarded  against  by 
accurate  chemical  control  of  the  acid  plant  and  by  constant  watch¬ 
fulness  on  the  part  of  the  entire  operating  force.  The  cause  of 
sulphate  or  gypsum  in  the  acid  may,  as  can  be  seen  from  the 


THE  ACID  PLANT 


135 

above  considerations,  lie  with  the  operation  of  the  sulphur  burners 
or  the  coolers  or  the  milk-of-lime  or  tower  system.  If  difficulty 
is  found  in  keeping  the  acid  free  from  sulphate  all  of  the  above 
possible  causes  should  be  carefully  investigated. 

Milk-of-Lime  Systems. 

The  best  known  milk-of-lime  systems  are  the  Stebbins  System 
and  the  Barker  System. 

Stebbins  System:  This  is  a  three-tank  system,  the  tanks  be; 
ing  placed  one  upon  the  other.  The  system  can  be  intermittent 
or  continuous  but  the  continuous  systems  are  preferable.  The 
gas  is  drawn  through  the  system  by  a  vacuum  pump  which  ex¬ 
hausts  the  excess  gas -from  the  highest  of  the  three  tanks. 

In  the  continuous  Stebbins  system,  milk-of-lime  is  supplied 
to  the  top  tank  and  flows  through  the  two  lower  tanks.  The  gas 
enters  the  lowest  tank,  passes  through  the  solution,  is  piped  from 
this  tank  to  the  bottom  of  the  second  tank,  through  which  it  then 
bubbles  in  the  same  manner,  and  finally  through  the  upper  tank. 
The  milk-of-lime  is  prepared  by  agitating  the  lime  with  hot  water 
in  an  iron  tank  provided  with  an  agitator.  This  tank  discharges 
into  a  large  wooden  tank  also  provided  with  an  agitator  in  which 
the  milk-of-lime  is  diluted  with  fresh  water  to  a  density  of  1° 
Baume.  From  this  tank  it  is  passed  through  a  filter  into  a  storage 
tank  where  it  is  held  until  required  for  the  absorbing  system.^ 
Provision  is  made  for  drawing  samples  from  the  lowest  tank. 

The  Stebbins  system  is  passing  out  of  use  on  account  of  the 
invention  of  more  efficient  equipment,  for  producing  acid. 

Barker  System:  This  system  is  the  most  generally  used  of 
the  various  tank  systems.  It  is  a  four-tank  system,  the  four  tanks 
being  placed  one  above  the  other.  The  milk-of-lime  is  pumped 
into  the  top  tank  and  overflows  in  succession  into  the  second, 
third  and  fourth  tanks.  From  the  bottom  of  the  fourth  tank  is 
pumped  to  the  top  of  a.  recovery  system  to  be  described  later. 
The  gas  enters  the  bottom  of  the  lowest  tank,  passes  through  the 
solution  into  the  bottom  of  the  second  tank  and  in  the  same  man¬ 
ner  into  the  third  and  fourth  tanks.  Ju.st  as  in  the  Stebbins 
system,  the  gas  is  drawn  through  the  system  by  means  of  a^  vac¬ 
uum  pump  connected  to  the  pipe  by  which  the  excess  gas  is  re¬ 
moved  from  the  highest  tank. 

In  the  Barker  system  the  tanks  are  placed  one  directly  above 
the  other  in  a  tower.  In  actual  practice  four  tanks  are  not  used, 
but  one  tall  tank  divided  into  four  compartments  by  means  of 
partitions.  The  recovery  or  reclaiming  system  used  with  the 
Barker  milk-of-lime  system  is  practically  the  same  as  that  used 
with  tower  installations  to  be  described  later. 

The  advantages  of  the  Barker  system  over  other  milk-of-lime 
systems  are  compactness,  lessened  expense  for  repairs  and  greater 
ease  of  cleaning.  It  is  also  easier  to  operate  the  Barker  system 


136  MODERN  PULP  AND  PAPER  MAKING 

in  a  continuous  manner  than  other  milk-of-lime  systems.  How¬ 
ever,  while  probably  the  best  of  the  milk-of-lime  systems,  this 
system  exhibits  a  great  many  disadvantages  when  compared  with 
tower  systems.  These  disadvantages  will  be  more  readily  under¬ 
stood  after  the  tower  system  has  been  discussed. 

Burgess  System:  In  this  system  the  gas  is  admitted  through 
hollow  agitator  arms  which  are  rotated  in  the  tanks. 

Tower  Systems. 

The  earliest  forms  of  acid  making  equipment  were  tower  sys¬ 
tems,  the  towers  consisting  usually  of  high  wooden  columns  of 
circular  cross  section.  The  towers  were  filled  with  lumps  of 
limestone  or  dolomite,  the  latter  mineral  being  a  limestone  which 
contains  a  high  percentage  of  magnesia.  The  gas  from  the  sul¬ 
phur  burner  entered  the  bottom  of  the  tower  and  rose  in  an  irreg¬ 
ular  manner,  its  passage  upwards  being  intercepted  and  broken 
by  the  limestone.  Water  was  sprayed  into  the  top  of  the  tower 
in  such  a  manner  that  it  would  flow  down  through  the  tower,  cov¬ 
ering  all  the  pieces  of  limestone  with  a  film  of  water  as  it  flowed. 

The  engineering  difficulties  connected  with  the  construction 
and  maintenance  of  towers  were  so  numerous  and  so  formidable 
that  the  earlier  types  of  towers,  such  as  those- designed  by  Mit- 
scherlich,  Ritter  and  Kellner,  etc.,  were  largely^  abandoned  in 
favor  of  the  milk-of-lime  systems  previously  described. 

However,  with  improved  facilities  for  constructing  towers, 
the  system  has  come  back  into  favor  to  such  an  extent  that  it  has 
largely  supplanted  milk-of-lime  systems  in  the  majority  of  sul¬ 
phite  mills.  The  most  efficient  tower  system  is  the  Jenssen,  the 
towers  of  which  are  constructed  of  re-enforced  concrete, lined  with 
acid  resisting  tile. 

The  following  is  a  description  (for  which  we  are  indebted  to 
the  G.  D.  Jenssen  Co.)  of  a  typical  installation  of  this  kind.  A 
hard  lead  fan,  directly  connected  to  a  variable  speed  motor  so  as 
to  allow  the  capacity  of  the  plant  to  be  carried  at  any  desired 
point,  blows  the  sulphite  gas  through  the  concrete  towers  which 
work  in  series.  After  the  gases  have  passed  through  the  first 
tower,  they  enter  the  second  tower  at  the  bottom  through  a  tile 
pipe.  The  unabsorbed  gases  (carbonic  acid,  nitrogen,  oxygen) 
pass  out  into  the  air  through  a  pipe  on  top  of  a  second  tower. 
The  feed  water  is  distributed  from  the  top  of  the  second  tower  in 
which  it  forms  a  very  weak  acid,  which  is  pumped  into  the  first 
tower  where  the  finished  acid  is  made.  The  grates  on  which  the 
limestone  rests  are  elevated  from  17  to  20  feet  above  the  gas  inlets 
and  the  space  between  the  gas  inlet  and  these  grates  is  filled  with 
a  wooden  checker  work  fixture.  The  reason  for  this  arrange¬ 
ment  is  to  allow  the  acid  to  be  saturated  with  free  SOo  before  the 
gas  strikes  the  limestone.  Careful  experiment  has  shown  that 
from  17  to  20  feet  of  wooden  checker  work  is  sufficient  to  bring 
the  acid  to  the  point  of  saturation.  Raising  the  grate  still  higher 


THE  ACID  PLANT 


137 

would  not  influence  the  content  of  free  SO2  to  any  extent.  By 
arranging  the  towers  in  this  way,  it  has  been  possible  to  produce 
with  15  to  16  per  cent  gas  and  a  water  temperature  of  5°  C.  a 
tower  acid  containing  4.5  per  cent  total  SO2,  3.1  to  3.2  per  cent 
free  SO2  and  such  an  acid  in  connection  with  a  proper  reclaiming 


Courtesy:  G.  D.  Jenssen  Co.,  Nezu  York. 

Fig.  70. — A  recent  installation  of  Jenssen  towers. 

system  and  proper  operation  of  the  digester  relief,  brings  the 
percentage  of  total  SO2  in  the  cooking  acid  up  to  7  per  cent  or 
higher. 

When  the  towers  have  been  in  operation  two  or  three  days 
they  are  reversed,  the  second  tower  being  used  as  the  first  and 
vice  versa.  This  allows  the  first  tower  to  be  charged  with  lime¬ 
stone  as  the  cover  on  top  can  be  removed  after  creating  a  slight 


138  MODERN  PULP  AND  PAPER  MAKING 

vacuum  with  a  steam  jet,  the  gas  in  this  way  being  prevented  from 
entering  the  charging  room.  The  high  efficiency  of  this  system 
is  demonstrated  by  the  fact  that  over  90  per  cent  of  the  gas  is 
absorbed  in  the  first  tower,  the  towers  being  operated  under 
forced  draft  and  with  a  large  volume  of  water.  For  this  reason 
it  has  been  found  that  cleaning  the  limestone  grates  is  a  thing  o 
the  past.  The  system  can  be  shut  down  on  Sunday  morning  and 
started  up  on  Monday  without  any  cleaning  whatever. 

With  this  system  the  regulation  is  very  simple,  there  being  only 
one  water  valve  to  attend  to,  and  the  system  is  frequently  run 
from  ten  to  twelve  hours  without  changing  the  water  valve. 

The  flexibility  of  the  system  is  as  great  as  any  milk-of-hme 
system.  If  a  higher  content  of  combined  SOg  is  desired  m  the 
acid  this  can  be  done  in  two  ways,  either  by  heating  the  feed  wa¬ 
ter  so  as  to  accelerate  the  chemical  actions  in  the  towers  or  by 
recirculating  some  of  the  acid  from  the  first  tower  back  to  the  top 
of  this  tower  again  which  will  raise  the  lime  content  to  any 

desired  point.  .  ,  1  -1,4. 

The  above  arrangement  of  the  towers  is  used  where  a  straight 

calcium  limestone  not  exceeding  8  to  10  per  cent  magnesium  car¬ 
bonate  is  at  hand. 

Where  a  limestone  or  dolomite  containing  as  high  as  40  to  45 
per  cent  magnesium  carbonate  is  to  be  used,  tower  construction 
has  to  be  changed.  It  is  well  known  that  calcium  carbonate  is 
easier  to  dissolve  than  magnesium  carbonate,  and  due  to  this  lack 
of  uniformity  in  the  solution  of  magnesium  and  calcium  car¬ 
bonate,  the  latter  is  first  attacked  by  the  gases  with  the  result 
that  the  surface  of  the  stone  crumbles  and  a  sludge  is  formed. 
In  order  to  dissolve  this  sludge  the  grates,  when  a  limestone  lugh 
in  magnesia  is  being  used,  should  be  elevated  40  feet  above  the  gas 
inlets  and  four  towers  should  be  used  in  order  to  obtain  sufficient 
capacity  to  cover  the  slower  absorption  ability  of  the  high  mag 

nesia  stone.  •  1  1  •  1 

Until  recently,  it  has  been  the  opinion  of  many  that  acid  nigh 
in  magnesia  was  to  be  preferred.  The  explanation  of  this  has 
been  that  magnesium  bisulphite  is  decomposed  easier  by  steam  in 
cooking  than  calcium  bisulphite  and  that  the  sulphates  of  mag¬ 
nesia  are  soluble  whereas  the  sulphates  of  calcium  are  insoluble. 
Possibly  these  facts  had  a  bearing  on  the  quality  of  pulp  pro¬ 
duced  in  former  days  when  sulphite  mills  used  acid  low  in  free 
SO2  and  high  in  lime.  Today,  however,  with  excellent  means  of 
reclaiming  the  digester  gases  and  obtaining  cooking  acid  contain¬ 
ing  from  5  to  7  per  cent  total  SOo,  the  preference  for  magnesia 
over  calcium  has,  in  the  writer’s  opinion,  absolutely  disappeared. 
Mills  having  changed  from  milk-of-lime  to  a  straight  calcium 
limestone  have  confirmed  the  above  experience. 

One  of  the  advantages  of  the  tower  system  is  lower  sulphur 
consumption.  The  tower  system  is  very  flexible  cornpared  with 
the  milk-of-lime  system.  The  output  or  the  composition  of  the 


Fig.  71, — Diagram  showing  construction  and  operation  of  Jenssen  tower 

system. 


139 


140  MODERN  PULP  AND  PAPER  MAKING 

acid  can  be  changed  easily  by  any  one  of  a  number  of  means  such 
as  changing  the  volume  of  water  admitted  to  the  towers,  altering 
the  temperature  of  the  water,  increasing  or  decreasing  the  spee 
of  the  fan  or  vacuum  pump,  etc.  The  upkeep  of  the  tower  sys¬ 
tems  is  much  more  economical  than  that  of  milk-of-lime  systems. 
In  the  milk-of-lime  systems  sulphate  or  gypsum  forms  quickly 
and  plugs  the  holes  in  the  bottom  of  the  tanks,  the  connecting 
pipes,  etc.  Acid  of  much  higher  strength  can  be  made  m  the 
towers  than  is  possible  with  the  best  milk-of-lime  systems.  More¬ 
over,  the  cost  of  lime  is  high  compared  with  that  of  limestone. 
Furthermore,  limestone  is  not  subject  to  deterioration  while  lime 
slacks,  especially  in  the  summer  time,  and  requires  special  storage 
facilities.  Also,  whereas  the  limestone  is  constant^  in  chemical 
composition,  the  lime  is  constantly  changing  and  it  is^  impossible 
to  estimate  the  quantity  of  lime  to  use  in  a  rnilk-of-lime  system 
without  making  new  calculations  on  the  basis  of  fiequent  and 
careful  chemical  analysis  of  raw  materials. 

Efficiency  of  Tower  Systems. 

The  tower  system  offers  the  great  advantages  of  economy  in 
power  and  materials,  ability  to  adjust  itself  quickly  and  easily  to 
changes  in  manufacturing  conditions  and  reliability  in  operation. 

It  is  stated  by  Henry  F.  Obermanns^  that  in  changing  from  a 
three  tank  milk-of-lime  system  (five  of  which  systems  were  re¬ 
quired  for  a  lOO-ton  mill)  to  a  tower  system  the  following  ad 
vantages  were  derived  i  *^Each  tank  system  had  its  own  vacuum 
pump  requiring  about  35  b.p.  or  a  total  of  175  1^-P-  vacuum 
pumps  alone.  To  this  is  to  be  added  another  150  h.p.  for  agi¬ 
tators  for  the  various  tanks.  On  the  other  hand,  the  entire 
power  necessary  for  the  operation  of  the  tower  system  amounts 
to  about  50  to  60  h.p.  for  the  operation  of  the  fan  and  water 
pumps.  This  means  a  saving  of  from  $10,000  to  $12,000  per 
annum.  With  the  old  system  operating  continuously  sulphur  con¬ 
sumption  ran  about  15  per  cent  on  basis  of  bleached  pulp,  or 
about  300  pounds  of  sulpbur  per  ton.  With  the  towers  the  con¬ 
sumption  is  from  ii^  per  cent  to  12  per  cent.  Further  saving  is 
in  the  substitution  of  limestone  for  burnt  lime.  Wear  and  tear  is 
very  small  as  compared  with  constant  repairs  and  replacements 
with  the  old  system.  In  labor  there  is  no  particular  saving,  as 
no  men  could  be  eliminated  with  the  introduction  of  the  towers, 
but  the  acid-maker  was  left  with  no  manual  labor  to  perform, 
thus  being  free  to  devote  all  his  time  to  proper  supervision.” 

Proper  Strength  of  Acid. 

Very  divergent  views  are  held  as  to  the  proper  strength  of 
acid  and  the  proper  proportions  of  free  and  combined.  It  used  to 
be  thought  that  acid  should  have  a  high  combined.  A  usual 
analysis  in  the  old  days  was  4.00  per  cent  total,  2.75  per  cent  free 

»  Technical  Association  Papers,  1918,  pg.  28. 


THE  ACID  PLANT 


141 

and  1,25  combined.  In  such  an  acid  only  70  per  cent  of  the  total 
is  free.  Modern  acid  makers  like  to  have  anywhere  from  78  to 
88  per  cent  of  the  total  acid  in  free  form. 

The  writer,  after  lengthy  experimentation,  lias  come  to  use 
an  acid,  with  wet  wood  and  a  cook  of  ten  to  ten  and  a  half 
hours  duration,  analyzing  4.65  per  cent  total,  3.50  free  and  1.15 
combined ;  for  dry  wood,  total  4.39  per  cent,  free  3.25  and  com¬ 
bined  1. 10  to  1. 15.  By  wet  wood  we  mean  wood  containing 
approximately  from|4o  per  cent  to  50  per  cent  moisture  and 
by  dry  wood  we  mean  wood  containing  27  per  cent  to  35  per 
cent  moisture.  The  above  strengths  are  the  strengths  of  the 
cooking  acid.  The  strength  of  the  raw  acid  is  about  3.60  per 
cent  total,  2.18  per  cent  combined  and  1.42  per  cent  free  in 
the  case  of  the  wet  wood ;  and  3.86  per  cent  total,  2.37  per  cent 
free  and  1.49  per  cent  combined  in  the  case  of  the  dry.  This 
acid  is  made  at  about  4.5°  Be.  the  strength  being  brought  up 
to  the  total  mentioned  with  reclaimed  acid.  For  cooking  bleached 
stock  stronger  acid  with  a  total  of  about  6  per  cent  is  preferable. 
The  above  figures  are  for  unbleached  stock.  The  above  figures 
are  all  based  on  the  use  of  ^-inch  chips  which  run  from  55  to 
60  per  cent  within  tjiis  specified  length  and  it  is  also  assumed  that 
dry  steam  is  supplied,  generated  at  150  pounds  boiler  pressure 
and  with  a  pressure  of  from  60  to  68  pounds  of  dry  steam  on  the 
digesters. 

However,  the  above  just  applies  to  certain  grades  of  sulphite 
requiring  definite  strength  and  quality.  The  writer  would  not 
hesitate  to  use  stronger  or  weaker  acid  were  the  conditions  differ¬ 
ent.  Newsprint  can  be  made  with  weaker  acid,  particularly  if 
the  wood  is  dry.  R.  E.  Cooper  states^  that  an  acid  (raw)  ana¬ 
lyzing  total  3.50  to  4.00  per  cent,  free  2.40  per  cent  and  com¬ 
bined  1.30  to  1.60  per  cent  is  satisfactory  for  newsprint.  This 
acid  when  strengthened  with  reclaimed  acid  analyzes  from  5  to  6 
per  cent  total,  4  to  5  per  cent  free  and  about  i  per  cent  combined. 
Robt.  B.  Wolf^  states  that  one  summer  the  acid  in  the  plant  he 
was  operating  dropped  from  6  per  cent  to  4.25  per  cent  and  the 
decrease  in  the  strength  of  the  pulp  was  so  noticeable  as  to  cause 
several  of  the  mill’s  customers  to  inquire  as  to  the  cause.  When 
a  refrigerating  plant  was  installed  and  the  acid  went  up  to  over 
5.5  per  cent  the  strength  test  of  the  paper  immediately  increased 
from  65  to  85.  Mr.  Wolf  explains  these  results  on  the  grounds 
of  the  higher  maximum  temperature  and  increased  cooking  time 
needed  with  the  weaker  acid.  He  states,  moreover,  that  the 
consumption  of  wood  per  ton  of  sulphite  was  markedly  affected. 
With  the  strong  acid  it  took  1.65  cords  of  wood  to  make  a  ton  of 
bleached  sulphite,  whereas  with  the  weaker  acid  it  took  2  cords. 

The  combined  should  be  kept  above  i  per  cent  if  possible, 
certainly  above  0.9  per  cent.  A  lower  combined  will  mean  using 

'  Guide  to  Sulphite  Pulp  Manufacture.  Paper,  Inc.,  New  York,  1918,  pg.  26. 

*  Technical  Association  Papers,  1918,  pg.  62. 


142 


MODERN  PULP  AND  PAPER  MAKING 

much  more  bleach  in  making  bleached  sulphite  and  also  the 
pulp  will  be  of  poorer  quality.  It  has  been  stated  by  bh'ot. 
McKee  that  letting  the  combined  drop  to  below  0.8  per  cent  will 
double,  or  even  treble,  the  bleach  consumption.  ^  ,;r  1 

Strong  acid  means  a  higher  sulphur  consumption.  Modern 
reclaiming  systems  make  possible  the  maintenance  of  acid 
strengths  that  would  have  been  out  of  the  question  before  such 
systems  were  used,  but  with  the  best  reclaiming  systems  there 
is  a  direct  relation  between  the  sulpnur  consumption  ^’^d  t  e 
strength  of  the  acid.  For  one  thing,  it  is  not  alwap  possible  to 
relieve  all  of  the  gas  to  the  reclaiming  system  before  blowing. 
In  one  mill  the  conditions  are  such  that  the  digesters  have  to  be 
blown  very  light  to  keep  the  temperature  down.  Tins  evolves 
blowing  at  a  time  when  the  acid  tests  1.6  per  cent  free,  which 
means  blowing  sulphur  into  the  air  at  the  rate  of  about  150  pounds 
per  ton  of  pulp.  Systems  for  reclaiming  the  fumes  from  the 
blow  pits  have  been  devised  to  take  care  of  just  such  cases  as 

^^^\heoretically  190  pounds  of  sulphur  should  be  required  to 
make  i  ton  of  spruce  sulphite  pulp.  Most  American  mills  use 
much  more,  some  as  much  as  300  pounds.  E.  R.  Barker  states 
that  certain  Scandinavian  mills  make  good  pulp  using  less  than 
190  pounds. 

Superheated  Steam. 

Some  pulp  makers  favor  the  use  of  superheated  steam  in  the 
digesters  It  is  certain  that  its  use  facilitates  the  maintenance 
of  the  strength  of  the  acid,  but  on  the  other  hand  there  are  num 
erous  disadvantages.  Further  comments  on  this  subject  will  be 
found  in  the  chapter  on  the  power  plant. 


Reclaiming  Systems. 

Recovery  towers  are  the  chief  feature  of  the  reclaiming  sys¬ 
tem.  These  are  usually  of  concrete  and  may  be  filled  with 
wooden  checker  work  or  with  logs  or  with  chemical  stoneware 
rings.  Dilute  acid  from  the  tower  system  ip  pumped  into  the 
top  of  the  reclaiming  tower  and  flows  down  it,  meeting  and  ab¬ 
sorbing  the  gas  from  the  relief  lines  of  the  digesters.  The  liquid 
never  absorbs  all  the  gas  and  the  uiuabsorbed  gas  fills  the  space 
in  the  tower  above  the  liquid.  This  makes  a  pressure  of  gas 
on  the  liquid  which  enables  it  to  hold  more  gas  in  solution  than 
if  air  were  present  above  the  surface  of  the  liquid,  which  is  an 

The  reclaiming  of  the  relieved  liquor  is  very  simple,  as  it  i'' 
simply  run  to  tanks,  from  which  it  is  mixed  with  the  raw  acid. 

The  gas,  however,  has  to  be  cooled  before  going  to  the  re¬ 
claiming  towers.  The  coolers  are  similar  to  those  used  for  the 
cooling  of  the  gas  from  the  burners.  The  effect  of  temperature 
on  the  strength  of  the  acid  is  very  marked.  Referpice  to  the 
diagrams  on  pages  127  and  128  will  show  how  rapidly  the  solu- 


THE  ACID  PLANT 


143 

bility  of  sulphur  gas  in  water  decreases  as  the  temperature  rises. 
Whereas  at  o°  C.  i  volume  of  water  will  dissolve  approximately 
8o  volumes  of  sulphur  gas,  at  40°  C.  it  will  only  dissolve  about 
19  volumes.  Consequently  cold  water  should  be  used  in  the 
towers,  the  reclaiming  system  should  be  kept  cold  and  all  pipe 
lines  containing  raw  or  cooking  acid  should  be  laid  out  with 
this  in  view.  In  some  mills  refrigerating  systems  have  had 
to  be  installed  to  keep  up  the  strength  of  the  free  acid  in  summer. 

Pressure  and  Vacuum. 

The  milk-of-lime  systems  were  worked  under  vacuum.  That 

is,  the  gas  was  drawn  through  the  system,  not  forced  through 

it.  One  milk-of-lime  system  was  introduced  operating  under 
pressure  (that  of  Tranche)  but  it  had  other  drawbacks  that 
prevented  its  wide  application.  Theoretically  the  tower  systems 
are  pressure  systems,  but  the  pressure  is  so  low  that  it  has  no 
effect  one  way  or  the  other  on  the  strength  of  the  acid.  With 
milk-of-line  systems,  however,  pressure  is  much  preferable  to 
vacuum  as  it  will  permit  of  an  acid  much  higher  in  free  SO2. 
Pressure  systems  are  more  used  in  Europe  than  in  America. 

Burning  Pyrites  instead  of  Sulphur, 

Pyrites  is  sulphide  of  iron,  containing  about  54  per  cent 
sulphur  and  46  per  cent  iron,  when  pure.  Commercial  pyrites 
is  rarely  pure.  The  mineral  pyrite  is  mixed  with  other  sulphides 
and  with  ordinary  rock.  However,  in  most  parts  of  the  United 
States  and  Canada,  supplies  of  pyrites  can  be  obtained  yielding 
from  33  per  cent  to  48  per  cent  sulphur. 

The  possibility  of  burning  pyrites  instead  of  sulphur  in  pulp 
mill  acid  plants  is  probably  chiefly  interesting  in  Canada,  since 
there  are  no  deposits  of  sulphur  in  that  country  and  the  pulp 
mills  there  secure  all  their  sulphur  from  the  deposits  of  the 
southern  United  States.  However,  as  the  practice  develops  it  may 
become  very  interesting  to  mills  located  in  those  portions  of  the 
United  States  remote  from  the  sources  of  supply  of  sulphur 
and  near  satisfactory  pyrites  deposits.  Several  Scandinavian 
mills  use  pyrites  with  excellent  results. 

The  manufacturers  of  sulphuric  acid  have  developed  the  art 
of  burning  pyrites  to  a  high  degree  of  efficiency.  However, 
several  conditions  enter  into  the  burning  of  this  material  for  pulp 
mill  purposes  that  are  not  met  with  in  the  sulphuric  acid  plant. 
The  manufacturer  of  sulphuric  acid  is  pleased  rather  than  other¬ 
wise  if  some  of  the  sulphur  burns  to  SO3  in  the  pyrites  furnaces. 
The  pulp  manufacturer  has  to  avoid  that  condition.  Tempera¬ 
tures  have  to  be  carefully  regulated.  Some  pyrites  ores  contain 
a  metal  known  as  selenium  and  the  presence  of  this  in  even 
very  small  proportions  is  detrimental  as  it  causes  the  SOg  to 
oxidize  to  SO3,  thus  forming  sulphates  in  the  digester  acid.  The 
presence  of  copper  is  also  undesirable. 


144 


MODERN  PULP  AND  PAPER  MAKING 


There  are  a  number  of  pyrites  burners  on  the  market,  pos 
sibly  the  best  known  of  these  being  the  Herreshoff  Furnace  and 
the  Wedge  Furnace.  Both  of  these  are  mechanically  opera  ed 
furnaces  with  circular  hearths  on  which  the  ore  being  roasted 
is  stirred  with  rotating  arms.  It  is  not  necessaiy  to  describe  these 
furnaces  here  in  detail  as  anyone  interested  in  the  possibilities 


Courtesy:  General  Chemical  Co.,  New  York. 

Fig.  71a. — Herreshoff  furnace  for  burning  pyrites. 


of  pyrites  in  the  pulp  mill  will  find  detailed  information  on  such 
equipment  in  standard  text  books  on  metallurgy  and  the  manu¬ 
facture  of  sulphuric  acid. 

Furnaces  of  the  rotary  kiln  type  have  also  been  used,  tne 
best  known  of  these  being  the  Jones  furnace  which  has  been 

used  in  a  sulphite  mill  in  Canada. 

Pyrites  burners  will  not  yield  as  rich  a  gas  as  sulphur  biwners. 
About  the  best  they  will  yield  is  12  to  16  per  cent  SO2.  On  the 
other  hand,  there  is  less  free  oxygen  in  the  gas,  which  is  an 
advantage.  A  mill  contemplating  using  pyrites  should  have  a 
large  tower  capacity,  since  about  30  per  cent  more  gas  will  have 
to  be  passed  through  the  towers  to  produce  acid  of  a  given 


THE  ACID  PLANT 


145 


strength.  Also  very  cold  water  for  the  towers  is  a  requisite. 
Granted  these  conditions  good  pulp  can  be  made  using  pyrites 
in  the  acid  plant.  It  is  all  a  matter  of  comparative  costs.  The 
first  cost  of  the  equipment  is  high. 

According  to  Dr.  A.  W.  G.  Wilson/  of  the  Canadian  Depart¬ 
ment  of  Mines,  a  pyrites  burning  equipment  for  a  lOO-ton  sul¬ 
phite  mill  would  consist  of : 

Two  mechanical  roasters,  provided  with  hopper  feeds,  belt 
conveyors  for  charging  ore  to  the  hoppers  and  removing  cinders 
to  the  cinder  bin. 

Main  flue,  with  dust  discharge  hoppers. 

Dust  chamber,  with  dust  discharge  hoppers. 

Auxiliary  cooler,  with  dust  discharge  hoppers. 

Fan,  driven  by  variable  speed  motor. 

Scrubbers,  with  liquor  tank  and  centrifugal  circulating  pump, 
and  driving  motor. 

Assuming  three  shifts  per  day,  three  furnace  men  and  three 
laborers  will  be  required  in  constant  attendance.  In  addition 
the  mechanical  equipment  will  require  daily  inspection  by  a  ma¬ 
chinist  and  occasional  repairs  and  adjustments. 

Dr.  Wilson  makes  some  careful  calculations  of  the  cost  of 
pyrites  burning  as  compared  with  sulphur  and  comes  to  the  con¬ 
clusion  that  for  Canadian  lOO-ton  mills,  paying  $30  or  more 
per  ton  for  sulphur,  that  a  daily  saving  of  $163  would  be  pos¬ 
sible.  This  would  pay  the  interest  and  depreciation  on  the 
plant  and  yield  a  very  satisfactory  profit. 

^  Paper  read  before  the  Technical  Section  of  the  Canadian  Pulp  and  Paper  Asso¬ 
ciation,  Montreal,  Jan.  30,  1918.  Reprinted  in  “Paper,”  Feb.  13,  1918,  pgs.  102-134. 


VIII.  The  Soda  Process. 


The  soda  process  for  the  manufacture  of  chemical  wood  pulp 
depends  on  the  chemical  fact  that  alkali  at  high  temperatures 
will  dissolve  all  the  other  constituents  of  wood  except  the  cellulose, 
leaving  the  latter  in  a  form  suitable  for  paper  manufacture. 

The  soda  process  is  much  older  than  the  sulphite  process  and 
is,  of  itself,  simpler.  However,  in  order  to  be  carried  on  at  a 
profit,  it  is  necessary  to  recover  the  soda  and  most  of  the  problems 
of  soda  pulp  manufacture  are  connected  with  the  operation  of 
the  recovery  department. 

Not  only  is  soda  pulp  necessary  for  certain  varieties  of  paper, 
but  the  soda  process  will  serve  to  utilize  many  kinds  of  wood 
that  cannot  profitably  be  dealt  with  by  the  sulphite  process. 

Poplar  is  the  principal  kind  of  wood  used  for  soda  pulp, 
but  some  spruce,  pine,  hemlock,  cottonwood,  etc.,  are  also  worked 
up  by  this  process. 

It  is  not  necessary  to  prepare  the  wood  so  carefully  for  the 
soda  process  as  for  the  manufacture  of  sulphite  pulp.  The  bark 
is  removed,  but  it  is  not  generally  considered  necessary  to  ex¬ 
ercise  the  extreme  care  to  get  rid  of  all  the  small  particles  of 
bark  that  is  usually  exercised  in  making  good  sulphite.  No  at¬ 
tempt  is  made  to  eliminate  knots  or  decayed  wood.  The  more 
drastic  solvent  power  of  the  soda  lye  readily  reduces  even  knots 
and  bark. 

The  wood  is  chipped  just  as  for  the  sulphite  process,  except 
that  the  chips  are  usually  a  little  smaller,  being  from  inch  to 
^  inch  in  length.  The  chips  are  screened  in  exactly  the  same 
manner  as  for  sulphite  pulp  and  are  then  conveyed  to  chip  bins 
ready  to  be  placed  in  the  digesters. 

In  the  older  soda  mills  rotary  digesters,  either  horizontal  or 
spherical,  similar  to  those  used  for  boiling  rags,  were  extensively 
used.  These  digesters  were  heated  with  steam  coils,  the  steam 
entering  through  the  trunnions  and  the  coils  rotating  with  the 
digester.  These  digesters  were  of  small  capacity  and  the  cost  of 
upkeep  was  high.  The  digesters  were  constructed  of  steel  plate 
without  any  special  lining  as  steel  plate  resists  the  action  of 
alkali  about  as  any  metal. 

These  rotary  digesters  have  largely  been  replaced  by  station¬ 
ary  vertical  digesters,  similar  to  those  used  for  the  sulphite 
process,  but  usually  somewhat  smaller,  although  some  soda  pulp 
mills  are  now  using  very  large  digesters,  even  larger  than  the 
usual  sulphite  digester.  In  most  cases  the  direct  cook  is  used  in 
these  digesters,  live  steam  being  introduced  at  the  base  of  the 

146 


THE  SODA  PROCESS 


147 

digester.  However,  in  a  few  cases  jacketed  digesters  have  been 
employed. 

A  great  deal  of  trouble  has  been  occasioned  by  the  impos¬ 
sibility  of  keeping  ordinary  riveted  steel  plate  digesters  tight 
when  filled  with  soda  lye.  Although  steel  plate  resists  the  soda 
lye  very  well,  leaks  develop  where  the  shells  are  riveted,  pre¬ 
sumably  because  of  electrolytic  action  set  up  between  the  shell 


Courtesy:  Fibre-Making  Processes,  Inc.,  Chicago,  III. 

Fig.  72. — Soda  digester  arranged  for  indirect  cooking. 

and  the  rivets,  the  composition  of  the  two  being  sufficiently 
dififerent  to  cause  this  effect. 

With  a  jacketed  digester,  if  the  steam  pressure  is  kept  in 
excess  of  the  pressure  within  the  digester,  any  leaks  will  be  in¬ 
wards  and  comparatively  harmless. 

Welded  digesters  are  now  on  the  market  and  are  being  used 


148  MODERN  PULP  AND  PAPER  MAKING 

by  some  of  the  large  manufacturers  of  soda  pulp  with  conspicu¬ 
ous  success.  These  digesters  provide  entire  freedom  from  leak¬ 
age.  The  size  in  which  such  digesters  can  be  furnished  is  con¬ 
stantly  increasing,  as  the  art  of  welding  advances,  and  some  have 
been  made  sufficiently  large  for  use  in  the  sulphite  process. 

Systems  for  circulating  the  liquor  have  been  employed  a  good 
deal  in  connection  with  the  soda  process.  One  important  mill 
uses  steam  injectors  for  this  purpose.  The  Morterud  process, 
whereby  the  liquor  is  heated  in  a  separate  heater  and  pumped 
through  the  digester  has  been  used  for  the  soda  process  with  con¬ 
siderable  success  in  Europe  and  is  now  being  introduced  in 
America.  This  process  has  the  advantage  that  the  liquor  is  not 
diluted  and  consequently  the  evaporating  problem  in  the  re¬ 
covery  plant  is  simplified. 

A  digester  of  the  stationary  type  7  feet  in  diameter  and 
29  feet  high  holds  about  MA  cords  of  chips  and  4,200  gallons 
of  liquor.  This  would  be  a  small  digester.  Soda  process  digesters 
as  large  as  19  feet  by  65  feet  have  been  used.  This  liquor  is 
caustic  soda  solution  usually  11.5°  to  12°  Baume  at  60°  F. 

When  the  digester  is  full  the  lid  is  bolted  on  and  the  .steam 
admitted.  The  pressure  is  brought  up  to  maximum  as  quickly 
as  possible  and  maintained  until  the  end  of  the  cook.  ^  In  this 
regard  this  is  a  much  simpler  process  than  the  sulphite  cook. 
Pressures  over  90  pounds  used  to  be  unusual  and  in  the  older  ac¬ 
counts  of  the  process  pressures  from  60  to  90  pounds  are  spoken 
of  as  good  practice,  but  in  the  modern  soda  mill  the  pressures 
are  much  higher,  125  or  130  pounds  being  quite  ordinary. 

The  length  of  the  cook  depends  chiefly  on  the  dryness  of  the 
wood.  The  diyer  the  wood,  the  more  rapidly  it  absorbs  the  caustic 
soda  solution.  Usually  the  cook  is  completed  in  from  6  to  8 
hours.  In  order  to  circulate  the  liquor,  the  pressure  is  relieved 
from  time  to  time.  This  causes  dilution  of  the  liquor  from  the 
new  steam  entering  and  loss  of  heat  units  and  is  one  of  the 
arguments  against  the  direct  cook  as  compared  with  the  indirect 
methods  where  forced  circulation  is  used,  because  in  the  soda 
process  there  is  no  reason  apart  from  promoting  circulation  for 
relieving  the  pressure  until  the  cook  is  completed,  i.  e.,  no  gas  is 
generated  during  the  process  which  has  to  be  relieved  as  is  the 
case  in  cooking  sulphite  pulp. 

When  the  cook  is  completed  the  valve  at  the  bottPm  of  the 
digester  is  opened  and  the  contents  blown  into  a  receiving  tank. 
This  tank  is  usually  elevated  above  the  wash  pans,  in  which  the 
liquor  is  eliminated  from  the  pulp,  as  the  digester  pressure  is 
sufficient  to  elevate  the  pulp  to  the  height  of  the  receiving  tank. 
The  steam  escapes  through  a  vent  at  the  top  of  the  tank,  this 
vent  usually  being  provided  with  baffles  to  prevent  any  pulp  or 
liquor  being  blown  or  splashed  out. 

The  contents  of  the  receiving  tank  are  next  run  into  the  first 
of  a  series  of  wash  pans  which  are  provided  with  perforated  false 


THE  SODA  PROCESS 


149 

bottoms  through  which  the  liquor  drains  from  the  pulp.  Dilute 
hot  liquor  from^a  certain  portion  of  the  recovery  system  is  then 
sprayed  on  the  pulp  in  the  first  pan,  which  it  frees  from  alkali 
to  a  certain  extent,  at  the  same  time  becoming  fortified  itself. 
Following  this  operation  more  and  more  dilute  liquor  and  finally 
clean  hot  water  is  sprayed  on  the  pulp  for  long  enough  to  re¬ 
move  the  last  traces  of  dissolved  intracellular  matter  and  alkali. 
This  water  goes  to  the  recovery  system  also  as  it  drains  from  the 
pulp. 

The  contents  of  the  digester  when  blown  are  of  quite  a  differ¬ 
ent  appearance  from  the  contents  of  a  sulphite  digester,  being 
dark  brown  and  in  some  cases  black,  and  having  a  distinctive 
empyreumatic  odor. 

The  pulp,  when  the  liquor  is  washed  from  it,  is  of  a  gray 
or  brown  color  which  it  does  not  lose  until  it  is  bleached. 

The  whole  principle  of  washing  the  contents  of  the  soda 
digester  is  to  thoroughly  get  rid  of  every  last  trace  of  alkali  and 
dissolved  intracellular  matter  without  diluting  the  wash  liquors 
any  more  than  is  absolutely  necessary,  as  all  these  liquors  have 
later  to  be  evaporated  to  recover  the  soda.  Very  small  traces 
of  liquor  left  in  the  pulp  render  bleaching  very  difficult  and  seri¬ 
ously  impair  the  value  of  the  product.  Excessive  use  of  wash 
water  makes  recovery  too  costly. 

For  these  reasons  the  pulp,  at  each  stage  of  the  washing,  is 
washed  with  the  liquor  from  the  pan  just  before  it  in  series,  and 
the  small  amount  of  fresh  water  used  for  the  final  washing  of 
a  lot^  of  pulp  passes  in  succession  through  the  whole  series  of 
washing  pans  or  tanks  (usually  four  or  five  in  number)  in  each 
succeeding  one  of  which  the  percentage  of  black  liquor  retained 
by  the  pulp  is  greater.  At  the  end  of  the  operation  the  liquor 
is  used  to  wash  the  pulp  fresh  from  the  digester,  as  mentioned 
above,  and  as  a  result  of  this  operation  is  brought  up  to  a  con¬ 
centration  approximating,  in  properly  conducted  plants,  about  55 
per  cent  of  the  original  strength.  The  capacity  of  the  wash  pans 
should  be  sufficient  that  no  liquor  will  ever  have  to  be  drained 
to  waste.  Of  course,  some  soda  is  unavoidably  lost,  but  if  less 
than  95  per  cent  of  the  soda  goes  to  the  evaporators  from  the 
pans  there  is  something  wrong  in  the  system. 

The  completely  washed  pulp  is  hosed  out  of  the  washing  pan 
in  exactly  the  same  manner  that  sulphite  pulp  is  hosed  from  a 
blow  pit,  which  has  been  described  in  the  chapter  on  the  sulphite 
process.  A  pump  elevates  the  stuff  to  the  screens.  The  re¬ 
mainder  of  the  treatment  of  soda  pulp  is  exactly  the  same  as 
already  described  for  sulphite  pulp.  However,  diaphragm  screens 
are  almost  altogether  used  for  soda  pulp.  The  reader  will  prob¬ 
ably  recollect  that  when  discussing  the  screening  of  sulphite  pulp 
we  described  both  diaphragm  and  centrifugal  screens  and  stated 
that  although  centrifugal  screens  were  more  efficient,  where  the 
quality  of  the  paper  being  produced  would  tolerate  their  com- 


Cooking  Conditions  Employed  At  Specific 


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Cooking  Conditions  Employed  At  Specific  American  Soda-Pulp  Mills — Continued 


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153 


154  MODERN  PULP  AND  PAPER  MAKING 

paratively  incomplete  screening  action,  the  manufacture  of  fine 
papers  required  diaphragm  screens.  Soda  pulp  is  used  chiefly 
for  good  book  and  writing  papers,  hence  the  use  of  diaphragm 
screens  in  such  mills  in  preference  to  centrifugal  screens. 

Recovery  Systems. 

Early  in  the  development  of  the  soda  process  it  was  realized 
that  it  would  be  necessary,  in  order  to  make  the  process  attain 
maximum  economy,  to  recover  and  re-use  the  alkali  in  the  waste 
liquor.  This  development  was  urged  forward  in  many  localities 
by  litigation  with  a  view  to  preventing  the  waste  liquors  from 
being  run  into  flowing  streams. 

To  clearly  understand  the  recovery  process,  the  reader  should 
remember  of  what  the  liquor  is  composed.  It  holds  two  main 
ingredients,  organic  matter  in  solution  and  carbonate  of  soda. 
Now,  when  sufficiently  concentrated,  the  organic  matter_  will 
burn,  yielding  a  considerable  amount  of  heat  which  can  be  utilized 
in  the  first  stages  of  concentration  of  the  liquor.  At  the  end 
of  the  process  we  will  have  a  mixture  of  carbonate  of  soda,  un¬ 
burned  carbon  and  incombustible  mineral  matter  from  the  wood 
(ash)  and  this  mixture  goes  by  the  name  of  “black  ash.” 

The  specific  gravity  or  density  of  the  liquor  at  the  commence¬ 
ment  of  the  recovery  process  depends  on  the  strength  of  the 
original  liquor  charged,  the  moisture  in  the  wood,  whether  the 
cook  was  with  direct  steam  or  by  the  indirect  method  and  the 
efficiency  of  the  washing  system.  In  one  American  mill  operating 
the  soda  process  on  a  large  scale  the  density  is  9.5°  Baume  at  6o°F. 
According  to  Griffin  and  Little  “it  is  possible  to  bring  the  mixture 
of  waste  liquor  and  wash  water  up  to  a  gravity  of  6°  to  9°  Baume 
at  i6o°F.  The  higher  gravity  is  very  rarely  reached,  and  in  some 
mills  the  liquors  going  to  the  evaporator  do  not  stand  over  3° 
to  4°  Baume  at  the  same  temperature.”  Griffin  and  Little  s  re¬ 
marks  were  written  in  1894  in  the  period  since  then  con¬ 
siderable  development  has  been  made  in  the  efficiency  of  the  soda 
process  and  their  figures  would  be  considered  rather  too  low  now. 

The  first  attempts  at  recovery  utilized  open  evaporating  pans. 
Such  inefficient  equipment  was  soon  abandoned  in  favor  of 
multiple  effect  evaporation  in  suitably  designed  equipment. 

Multiple  Effect  Evaporation 

The  theory  of  multiple  effect  evaporation  is  a  vast  and  com¬ 
plex  subject,  but  the  following  brief  explanation  of  the  prin¬ 
ciple  may  be  helpful.  The  boiling  point  of  water  becoming  lower 
as  the  pressure  is  decreased  (i.  e.,  the  vacuum  increased),  it  is 
possible  to  make  water  evaporate  from  a  solution  being  concen¬ 
trated  at  a  lower  temperature  by  decreasing  the  pressure.  When 
water  is  boiled  at  atmospheric  pressure  it  boils  at  212°  JP.  and 
the  vapor  given  off  has  also  this  temperature.  In  addition  to 
the  heat  units  it  possesses  simply  by  virtue  of  being  at  212°  F., 


.-r 


155 


156  MODERN  PULP  AND  PAPER  MAKING 

it  also  possesses  a  large  additional  number  of  heat  units  that 
have  been  put  into  it  in  converting  liquid  water  into  water  vapor, 
or  steam.  This  heat  will  again  be  given  up  when  the  steam  is 


Courtesy:  Swenson  Evaporator  Company,  Chicago,  III. 

Fig.  74. — Typical  modern  evaporator. 

This  is  a  rectangular  evaporator  with  horizontal  tubes  located  near 
the  bottom  of  each  effect.  It  is  made  up  in  sections  of  heavy  cast  iron 
nlates  with  machined  and  drilled  faces  and  flanges.  The  assembled  cast¬ 
ings  are  bolted  together  with  a  suitable  packing  material  usually  sheet 
asbestos— making  a  vacuum  type  joint.  There  is  a  steam  chest  at  each 
end  cast  as  an  integral  part  of  the  vertical  tube  sheet.  Each  tube 
passes  through  both  tube  sheets  and  is  packed  by  special  packing  platp 
and  rubber  gaskets,  thus  insuring  vacuum  tightness  and  resistance  to 
high  temperature. 


condensed.  It  is  called  the  latent  heat  of  steam.  A  pound  oi 
steam  at  212°  F.  will  have  about  1146  units  of  heat,  of  which 
about  964  will  be  in  the  form  of  latent  heat. 

Now,  a  multiple  effect  evaporator  is  really  a  series  of  boilers, 
so  arranged  that  the  steam  from  the  first  boiler,  or  “effect, 
will  be  carried  over  and  used  as  the  heating  agent  in  the  next 
effect.  The  second  effect  is  able  to  boil  at  a  lower  temperature 
than  the  first  owing  to  the  maintenance  of  a  partial  vacuum. 
The  steam  from  the  second  effect  goes  to  a  third,  which  operates 
at  a  still  greater  vacuum  and  thus  to  a  fourth,  and  perhaps  even 
fifth  and  sixth  effects.  Four  effects  is  a  usual  number  in  prac¬ 
tice.  Finally  the  steam  from  the  last  effect  goes  to  a  condenser. 


THE  SODA  PROCESS  157 

Equipment  utilizing  this  principle  has  been  designed  with 
such  engineering  skill  as  to  make  almost  perfect  utilization  of  the 
heat  supplied  to  the  machine.  The  first  multiple  effect  evaporators 
used  in  the  paper  industry  were  of  the  well-known  Yaryan  type, 
and  although  these  evaporators  have  largely  been  replaced  in 
recent  years  by  equipment  of  improved  design  (such  as  the  Scott, 
Swenson,  Zaremba,  Buffalo,  Badger-Webre  and  Kestner  evap¬ 
orators),  there  are  still  a  good  many  of  them  in  use  and  a  descrip¬ 
tion  will  not  be  out  of  place. 

Yaryan  Evaporator. 

Each  effect  of  this  evaporator  is  like  a  boiler  with  a  number 
of  horizontal  pipes  arranged  in  coils  parallel  to  the  shell.  A 
supply  pipe  feeds  the  liquor  into  a  header  at  the  back  of  the 
machine  from  which  the  coils  lead.  The  steam  is  admitted  into 
the  shell  surrounding  the  coils.  At  the  front  of  the  machine  the 
coils  end  in  a  header  which  serves  as  a  separator,  separating 
the  vapor  from  liquor  and  foam,  and  in  which  a  partial  vacuum 
is  maintained.  The  difference  between  the  pressure  at  which  the 
liquor  is  supplied  and  the  partial  vacuum  in  the  front  of  the  ma¬ 
chine  keeps  the  liquor  constantly  moving  forward,  forming  a 
film  on  the  surface  of  the  tubes,  and  in  this  way  a  new  surface  of 
liquid  is  constantly  exposed  to  the  action  of  the  steam.  The 
liquor  from  the  separator  of  the  first  effect  is  pumped  into  the 
second  effect  and  the  vapor  from  the  first  effect  *13  supplied 
to  the  shell  of  the  second  effect  to  give  up  its  heat,  and  the  opera¬ 
tion  is  repeated  for  as  many  effects  as  there  may  be.  The  liquor 
is  usually  concentrated  from  its  original  density  to  from  32*  Be. 
to  40°  Be.  at  60°  F.  Of  course,  the  concentration  could  be 
carried  much  higher  in  modern  evaporators,  but  this  is  not  done 
because  of  the  difficulty  of  pumping  such  very  thick  liquors. 
Moreover,  the  further  evaporation  of  such  liquors  is  not  neces¬ 
sary  as  from  37°  Be.  to  40°  Be.  has  been  found  a  good  strength 
for  burning. 

Disc  Evaporators. 

Sometimes  only  part  of  the  water  is  driven  off  in  multiple 
effects,  the  remainder  being  removed  with  disc  evaporators.  One 
of  the  best  known  disc  evaporators  for  use  in  the  evaporation  of 
waste  liquor  is  the  Carlson  and  Waern  evaporator.  This  machine 
employs  the  principle  of  exposing  a  thin  film  of  liquid  to  direct 
heat  over  a  large  area.  This  is  accomplished  by  rotating  a  wheel, 
or  series  of  wheels,  made  up  of  thin  steel  plates,  so  that  the 
,  plates  are  alternately  dipped  in  the  liquid  and  then  exposed  to, 
the  hot  gases  which  pass  through  the  evaporator  in  such  a  man¬ 
ner  that  they  come  in  contact  with  the  exposed  surfaces  of  all 
the  plates  or  discs.  The  moisture  is  absorbed  from  the  film 
of  liquid  and  passes  in  the  form  of  vapor  to  a  stack,  or  to  a  re¬ 
claiming  apparatus,  as  the  case  may  be.  While  these  evaporators 


158  MODERN  PULP  AND  PAPER  MAKING 

are  frequently  used  alone,  they  can  be  used  most  efficiently  to 
follow  a  preliminary  evaporation  in  some  form  of  multiple  effect 
evaporator.  In  the  sulphate  process  they  are  usually  used  alone 
as  the  liquors  are  usually  not  so  dilute  as  in  the  soda  process 
owing  to  the  greater  use  of  indirect  cooking  in  sulphate  mills. 
These  evaporators  have  the  advantage  that  they  will  handle  thick, 
gummy  liquors  that  would  clog  tube  evaporators. 

Rotary  Furnaces. 

The  liquor  from  the  evaporators  is  sufficiently  concentrated 
that  it  will  support  its  own  combustion  when  introduced  into  the 
rotary  furnace.  A  storage  tank  heated  with  a  steam  coil  should 
be  placed  in  the  system  between  the  evaporators  and  the  rotary 
furnace,  and  a  by-pass  should  be  installed  so  the  liquor  can  go 
direct  from  the  evaporators  to  the  rotary  when  circumstances 
permit.  In  this  way  the  maximum  amount  of  heat  can  be  con¬ 
served.  These  furnaces  consist  of  two  parts,  the  rotating  part 
and  the  stationary  part.  The  stationary  part  is  a  fire-box,  con¬ 
structed  either  of  steel-plate  lined  with  fire-brick,  or  of  fire-brick 
held  in  place  by  iron  bands.  It  is  fitted  with  a  grate  for  burning 
coal  or  wood,  or  with  equipment  for  burning  gas  or  oil.  It 
opens  into  the  rotating  part  of  the  furnace.  The  rotating  part 
is  a  cylindrical  steel-plate  shell,  lined  with  fire-brick.  It  is  usually 
from  8  to  9  feet  in  diameter  unlined  and  from  14  to  30  feet  long. 
The  lining*  decreases  the  diameter  about  i  ft.  According  to 
Spence^  it  requires  about  i  lb.  of  coal  burned  in  the  fire-box  to 
produce  6  lbs.  of  ash  in  a  14-foot  rotary,  while  i  lb.  of  coal  will 
produce  12  lbs.  of  ash  in  a  30-foot  rotary.  When  burning  liquor 
from  cooking  of  hard-wood,  70  lbs.  of  ash  per  sq.  ft.  of  burning 
surface  per  24  hrs.  is  considered  good  and  this  is  increased  about 
10  per  cent  for  more  resinous  woods  such  as  spruce,  pine,  poplar, 
etc.  However,  the  larger  rotaries  cause  more  loss  of  soda  up 
the  stack  owing  to  the  increased  draft  required.  The  furnace 
is  caused  to  rotate  slowly.  This  is  usually  accomplished  by  iron 
rings  which  rest  on  flanged  wheels,  the  axles  of  these  vrheels 
resting  in  journals  supported  by  masonry.  The^  rotation  is  ac¬ 
complished  with  a  worm  drive  and  a  gear  and  pinion.  The  liquor 
is  run  into  the  end  of  the  rotating  cylinder  farthest  from  the 

^Report  of  the  Committee  on  Soda  Pulp,  T.  A.  P.  P.  I.,  IQIP- 
1919,  pg.  619. 


“Paper,”  Feb.  12, 


159 


Fig.  74a.  A  Modern  Multiple-Effect  Evaporator  Installation  in  a  Large  Pulp  Mill. 


i6o  MODERN  PULP  AND  PAPER  MAKING 

fire-box  and  gradually  runs  forward,  burning  as  it  moves,  and 
the  black  ash  falls  out  of  the  cylinder  through  an  opening  located 
just  back  of  the  fire-box.  The  heat  produced  in  this  furnace  is 
generally  utilized,  either  in  the  disc  evapoiators  oi  foi  opeiating 
a  boiler  which  supplies  steam  to  the  multiple  effect  evaporators, 
of  for  a  preheater  for  the  liquor  going  to  the  evaporatois.  The 
black  ash  used  to  be  conveyed,  either  by  trucks,  or  by  a  con¬ 
veyor  to  the  leaching  and  causticizing  department,  but  is  now 
more  usually  discharged  into  a  tank  situated  in  a  pit  under  the 
discharge  of  the  rotary. 

Causticizing. 

The  black  ash  is  leached  in  a  system  of  leaching  tanks  so  as 
to  effectually  wash  out  all  the  soda,  leaving  only  black,  finely 
divided  carbon,  which  is  a  by-product.  Some  modern  soda  mills 
work  this  up  into  a  salable  substance  used  for  filtering  and  de¬ 
colorizing  purposes.  Sufficient  new  carbonate  of  soda  is  added 
at  this  stage  to  bring  the  liquor  up  to  the  required  strength.  As 
a  rule  from  lo  to  30  per  cent  of  the  soda  used  is  lost  at  every 
operation  and  this  soda  has  to  be  replaced  at  this  stage  in  the 
process.  The  soda  has  to  be  causticized  before  it  is  added  to  the 
liquor.  The  chemistry  of  the  causticizing  operation  consists  m 
converting  carbonate  of  soda  into  caustic  soda,_  or  sodium  hy 
droxide.  This  is  done  with  freshly  burned  lime.  Equipment  for 
causticizing  has  been  developed  to  a  high  degree  of  efficiency 
by  chemical  engineers  because  this  operation  is  important  in  other 
industries  as  well  as  in  paper  making.  It  is  a  necessary  part  of 
the  manufacture  of  soap,  the  refining  of  oils  and  of  many  other 
lines  of  manufacture. 

The  standard  system  of  causticizing  is  to  add  the  lime  to  the 
solution  of  soda  ash  in  a  tank  fitted  with  an  agitator  and  a 
false  bottom  full  of  perforations.  Freshly  burned  lime  is  added 
to  the  liquor  in  the  proportion  of  about  60  pounds  of  lirne  for 
every  100  pounds  of  carbonate  of  soda  (soda  ash)  in  the  liquor. 
The  lime  mud  produced  is  thoroughly  washed  to  remove  all  traces 
of  caustic  soda.  This  is  done  by  repeating  the  process  of  wash¬ 
ing,  settling  and  decantation  until  the  sludge  is  as  free  from  alkali 
as  circumstances  will  permit. 

Variations  of  the  causticizing  tank  have  been  devised.  In 
some  forms  there  is  a  suspended  basket  for  the  lime.  The  caus¬ 
ticizing  tank  is  provided  with  steam  connections  for  heating  the 

contents.  _  .  , 

In  some  mills  the  lime  mud  is  recovered  by  burning  in  a  rotary 
furnace  to  form  lime  again.  This  requires  a  huge  furnace,  ex¬ 
pert  attention  and  a  lot  of  fuel,  and  has  not  generally  been  con¬ 
sidered  practical,  at  least  where  good  lime  can  be  obtained  at  a 
reasonable  price. 

The  labor  cost  of  the  causticizing  process  is  high  and  it  re¬ 
quires  a  lot  of  floor  space,  tanks,  piping,  steam  connections,  etc. 


THE  SODA  PROCESS  i6i 

Causticizing  Processes  Employing  Eiltration:  Owing  to  the 
length  of  time  required  for  ordinary  settling  and  decantation, 
filter  presses  have  been  introduced  in  some  causticizing  plants. 
The  ordinary  plate  and  frame  filter  press  is  too  well  known  to 
require  detailed  description  here.  It  has  the  drawbacks  of  small 
capacity  and  requiring  a  great  deal  of  labor. 

Improved  forms  of  filter  press,  such  as  the  Kelly  press  and 
the  Sweetland  press  have  endeavored  to  overcome  these  defects 
by  giving  an  increased  capacity  for  the  space  occupied  and  the 
time  required  in  the  operation. 

When  filter  processes  are  used  for  causticizing  in  soda  mills 
the  sludge-containing  liquor  from  the  causticizer  should  be  sent 
to  a  settling  tank,  from  which  one  decantation  of  the  strong 
liquor  is  made.  The  sludge  from  this  tank  is  sent  direct  to  the 
filter  presses  and  the  filtrate  from  the  presses  is  mixed  with  the 
decanted  liquor.  The  filter  press  cake  is  then  washed  and  the 
wash  water  united  with  the  strong  liquor  to  whatever  extent  may 
be  advisable. 

Rotary  continuous  filters  are  much  more  efficient  tlian  filter 
presses  for  this  sort  of  operation.  These  consist  of  a  tank  in 
which  is  suspended  a  revolving  drum,  the  surface  of  which  is 
composed  of  a  number  of  compartments,  covered  with  a  wire 
cloth  or  other  filtering  medium.  Each  compartment  is  connected 
to  a  trunnion  fitted  with  an  automatic  device  so  suction  or  pres¬ 
sure  can  be  applied  to  each  compartment  at  the  particular  stage 
in  the  operation  where  it  is  required.  When  the  drum  is  im¬ 
mersed  in  the  tank,  that  portion  is  supplied  with  suction  and  the 
sludge  is  drawn  against  the  filtering  surface.  When  that  portion 
comes  out  of  the  bath  of  liquor  in  the  tank,  pressure  is  applied 
and  the  film  of  sludge  is  forced  off,  this  action  frequently  being 
assisted  by  a  doctor  blade.  These  machines  are  not  unlike  pulp 
thickeners  or  wet  machines,  used  in  the  pulp  industry,  in  their 
general  principle. 

Dorr  Causticizing  System. 

The  Dorr  Continuous  Cauticizing  System  embodies  an  attempt 
to  avoid  the  evils  of  the  ordinary  system  of  causticizing  by  inter¬ 
mittent  agitation  and  successive  washings  and  decantations.  This 
system  applies  to  the  problem  principles  long  recognized  as  sound 
in  the  washing  of  precipitates  and  employed  in  metallurgical 
plants.  It  makes  the  whole  process  continuous,  effecting  a  marked 
saving  in  labor  and  power  and  reduction  to  a  minimum  of  the 
losses  in  charging,  agitating,  decanting  and  washing,  due  to  elimi¬ 
nation  of  the  personal  element  which  is  such  a  big  factor  in  in¬ 
termittent  work.  This  system  is  now  installed  at  a  recently 
erected  soda  pulp  mill  in  the  South.  The  causticizing  plant  pro¬ 
duces  50  tons  100  per  cent  caustic  soda  per  twenty-four  hours 
in  the  form  of  either  a  10°  Baume  or  14°  Baume  liquor. 

The  illustration  shows  a  plan  of  a  complete  Dorr  causticizing 


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162 


THE  SODA  PROCESS 


163 

plant  and  a  convenient  arrangement  of  the  mechanical  equip¬ 
ment  used.  Before  going  into  details  regarding  the  flow  of 
liquor,  etc.,  through  the  plant,  a  description  is  given  of  the  in¬ 
dividual  machines  used. 

In  the  lime  slacking  circuit  a  standard  tube  mill  and  Dorr 
classifier  are  used.  This  latter  machine,  a  cut  of  which  is  shown, 
consists  of  a  settling  tank  in  the  form  of  an  inclined  trough  open 
at  the  upper  end.  The  feed  enters  near  the  center  and  the  liquid 
and  the  slow  settling  solids  overflow  at  the  closed  end  while  the 
sand  or  quick  settling  solids  are  conveyed  along  the  bottom  by 
mechanically  operated  reciprocating  rakes  and  after  emerging 
from  the  liquor  are  discharged  at  the  open  end. 

The  tube  mill  and  classifier  as  shown  on  the  plan  are  laid  out 
to  operate  in  closed  circuit,  which  system  consists  of  connecting 
a  grinding  mill  and  a  classifier,  so  that  the  mill  discharge  goes  to 


Fig.  76. — Dorr  Classifier. 


the  classifier  and  all  finished  product  is  overflowed,  while  the 
unfinished  product  from  the  sand  discharge  end  is  returned  to 
the  mill.  In  this  way  the  circulating  load  may  be  several  times 
the  tonnage  being  ground  but  the  finished  material  is  removed 
from  the  circuit  as  fast  as  made. 

Owing  to  the  fact  that  all  parts  of  the  classifier  moving  one  on 
another  are  suspended  above  the  liquor  and  that  the  average  speed 
at  which  the  rakes  are  operated  is  approximately  ten  strokes 
per  minute,  the  upkeep  of  this  machine  is  very  light.  The  horse 
power  required  to  operate  a  classifier  of  this  type  is  less  than 
jA  horse  power. 

The  reaction  between  the  soda  ash  or  soda  ash  liquor  and  lime 
takes  place  in  agitators,  a  cut  of  one  of  which  is  shown. 

As  will  be  noted,  these  agitating  tanks  are  equipped  with  a 
central  vertical  pipe  carried  by  a  shaft  supported  from  the  top  of 
the  tank  and  equipped  with  two  arms  to  which  are  attached  plow 
blades  which  travel  around  the  bottom  of  the  tank  and  move 


i64  modern  pulp  AND  PAPER  MAKING 

the  lime  mud  to  the  center.  Air  is  introduced  at  the  bottom  of 
the  vertical  pipe,  making  it  can  air  lift,  so  that  the  solids  which 
are  plowed  to  the  center  are  raised  and  distributed  by  means  of 
the  launders  which  are  attached  to  the  pipe  just  above  the  liquor 
level  and  which  rotate  with  it.  The  reaction  agitator  tanks  are 
equipped  v/ith  covers  and  steam  coils,  a  temperature  of  about 
95°  C.  being  maintained  for  causticizing.  The  mechanisms  are 
belt  driven  through  bevel  gears  and  make  about  three  revolutions 
per  minute ;  this  slow  speed  and  the  fact  that  no  submerged  bear¬ 
ings  are  used  tend  to  a  minimum  of  attention  and  repairs. 

Owing  to  the  fact  that  the  whole  agitator  mechanism  can  be 


Courtesy :  The  Dorr  Co.,  New  York. 

Fig.  77. — Dorr  Agitator. 

readily  raised,  no  difficulty  is  encountered  in  starting  up  after  a 
shut  down.  The  horse  powar  will,  of  course,  vary  with  the  size 
of  the  agitator  used,  but  can  be  taken  at  approximately  horse 
power  to  rotate  the  arm.  Approximately  10  cu.  ft.  of  free  air 
per  minute  at  15  lbs.  pressure  will  be  required  for  the  air  lift. 

To  collect  the  caustic  liquor  and  wash  the  lime  mud  formed, 
Dorr  Continuous  Thickeners  are  used. 

This  machine  consists  of  a  slow  moving  mechanism  set  in  a 
tank  and  is  made  up  of  a  central  vertical  shaft  driven  by  a  worm 
wheel  and  worm,  the  shaft  having  radial  arms  attached  to  its 
lower  end.  These  arms  carry  plow  blades  set  at  an  angle  which, 
through  the  rotation  of  the  mechanism,  move  the  settled  material 
to  a  discharge  opening  at  the  center  of  the  tank. 


THE  SODA  PROCESS 


165 


Fig.  78. — Dorr  Continuous  Thickener. 

The  average  speed  at  which  a  thickener  mechanism  is  operated 
is  about  one  revolution  in  six  minutes,  the  horse  power  required 
being  approximately  horse  power.  Here  again,  due  to  the 
slow  speed  and  the  fact  that  there  are  no  submeigcd  bearings,  the 
upkeep  and  operating  cost  is  extremely  low.  The  slow  blirring  ac- 


MODERN  PULP  AND  PAPER  MAKING 


i66. 

tion  produced  by  the  rotation  of  the  arms  causes  some  condensa¬ 
tion  of  the  lime  mud  by  squeezing  out  a  part  of  the  water  en¬ 
trained  in  the  floes  so  that  a  denser  underflow  can  be  obtained 
than  is  possible  in  the  case  of  undisturbed  settling. 

To  control  the  underflow  of  the  thickeners  and  to  raise  the 
lime  mud  to  a  sufficient  height  to  discharge  it  into  the  next  thick¬ 
ener  in  the  series,  Dorreo  diaphragm  pumps  are  used. 

This  pump  is  a  form  of  diaphragm  pump  with  flat  valves 
which  has  been  designed  to  give  continuous  operation  with  mini¬ 
mum  repair  costs.  It  is  entirely  self-contained,  a  heavy  frame 
being  used  to  support  the  eccentric  shaft  and  drive  pulley.  The 


Thtehaner 


FIG- 


Courtesy;  'The  Dorr  Co.,  New  York. 

Fig.  79. — Diagram  illustrating  flow  of  liquor  in  soda  mill  through  digesters, 
recovery,  and  causticizing  plants. 


eccentric  is  adjustable  so  that  the  length  of  stroke  can  be  set 
from  o"  to  3".  The  speed  at  which  these  pumps  are  operated 
vary  from  20  to  40  strokes  per  minute. 

The  density  of  the  thickener  underflow  is  controlled  by  the 
number  of  strokes  per  minute,  the  length  of  these  strokes,  and 
by  allowing  air  to  enter  the  bowl  compartment  of  the  pump.  Once 
a  plant  is  tuned  up,  this  type  of  pump  requires  but  little  atten¬ 
tion.  There  is  no  upkeep  cost  except  for  an  occasional  change 
of  diaphragm.  The  rubber  diaphragms  are  readily  replaceable 
without  dismantling  the  pump,  the  average  life  being  about  two 
months. 

The  discharge  pipe  of  each  thickener  tank  is  directly  coupled 
to  the  suction  of  one  of  these  pumps  and  usually  two  valves  are 


THE  SODA  PROCESS 


167 

placed  in  this  line.  A  high  pressure  water  pipe  should  be  con¬ 
nected  so  that  in  case  this  suction  pipe  becomes  choked  one  of  the 
valves  may  be  closed  and  the  water  turned  on  to  flush  it  out. 

Now,  referring  to  the  drawing  on  page  166  which  diagramatic- 
ally  portrays  the  flow  of  liquor  through  the  digesters,  soda  ash 
recovery,  and  causticizing  plants.  It  will  be  observed  that  all  of 
the  water  entering  the  system  is  introduced  at  No.  3  thickener 
where  the  pump  discharges  its  mud  drawn  from  No.  2  thickener 
to  the  mixing  launder.  This  launder  is  a  steel  trough  with  baffles 
laid  in  the  bottom  so  that  the  lime  mud  and  water  are  thoroughly 
mixed  to  form  a  uniform  feed  for  the  thickener. 

The  clear  liquor  overflowing  No,  3  thickener  joins  the  lime 
mud  from  No.  i  thickener  and  is  mixed  with  it  in  like  manner  to 
form  a  homogeneous  feed  for  No.  2  thickener.  The  clear  liquor 
overflowing  No.  2  goes  to  the  black  ash  leaching  cells  and  the 
effluent  from  these,  after  being  built  up  with  dry  soda  ash,  is  par¬ 
tially  used  in  the  closed  circuit  lime  slacking  system,  the  balance 
going  direct  to  the  reaction  agitators. 

Again  referring  to  the  plan  it  will  be  seen  that  the  slime  slack¬ 
ing  operation  is  carried  out  by  means  of  a  standard  tube  mill 
working  in  closed  circuit  with  a  Dorr  classifier  as  described.  A 
small  crusher  is  provided  to  reduce  the  lump  lime  to  a  maximum 
of  2  inches,  after  which  it  is  elevated  to  a  lime  storage  bin  as 
shown. 

A  mechanical  feeder,  adjustable  to  close  control,  delivers  the 
crushed  lime  from  the  bin  to  the  grinding  mill.  By  the  operation 
of  this  continuous  system  of  making  milk  of  lime,  all  handwork 
is  eliminated,  the  waste  of  lime  and  the  labor  required  for  clean¬ 
ing  out  sand  from  slacking  tanks  is  obviated  and  absolute  uni¬ 
formity  of  the  milk  of  lime  is  assured. 

Any  unburned  lime  rock  or  silica  is  taken  care  of,  as  they  are 
ground  to  such  a  fineness  before  leaving  this  system  that  they 
pass  through  the  reaction  agitators  and  thickeners  mixed  with 
the  lime  mud  formed  and  so  cause  no  trouble. 

By  the  use  of  a  classifier  working  in  closed  circuit  with  a  tube 
mill,  the  grinding  efficiency  is  raised  to  a  maximum  and  small 
mills  which  require  little  power  can  be  used  so  that  continuous 
lime  slacking  by  this  method  means  a  saving  of  power  over  slack¬ 
ing  in  tanks  with  paddle  agitators. 

The  percentage  recovery  of  caustic  soda  by  the  washing  proc¬ 
ess  will  depend  upon  the  number  of  thickness  used  and  the 
amount  of  wash  water  that  may  be  added,  the  latter  depending 
upon  the  density  of  finished  liquor  that  is  required.  When  pro¬ 
ducing  a  15°  Be.  liquor  and  using  three  thickeners,  a  99.7  per 
cent  recovery  of  caustic  soda  is  assured. 

One  drawback  of  the  Dorr  system  is  that  it ‘must  be  wasteful 
of  heat  as  the  thickeners  are  extensive  and  shallow.  Not  only 
will  this  cause  heat  losses  but  the  room  will  tend  to  be  very 
humid,  especially  in  cold  weather. 


i68  MODERN  PULP  AND  PAPER  MAKING 

Efficiency  of  Causticizing  Systems. 

The  following  comments  on  the  relative  efficiency  of  the  vari¬ 
ous  systems  discussed  above  is  largely  taken  from  an  article  in 
“Paper”  for  October  3,  1917. 

Taking  as  a  basis  a  mill  producing  about  100  tons  of  soda  pulp 
from  poplar  wood,  the  actual  alkali  required  daily  would  ap¬ 
proach  100,000  pounds  of  caustic  and  be  contained  in  about 
160,000  gallons  or  21,040  cubic  feet.  The  amount  of  calcium 
carbonate  resulting  from  the  chemical  reaction  would  be  about 
equal  to  the  amount  of  alkali. 

To  install  the  usual  sedimentation  and  decantation  process 
would  require  a  tank  floor  space  of  15,000  square  feet  provided 
only  one  tank  volume  is  turned  out  every  twenty-four  hours.  A 
tank  should  make  two  complete  cycles  daily  and  in  this  event  the 
floor  space  would  be  reduced  half  or  7,500  square  feet._  This 
alone  would  call  for  a  building  75  feet  'by  100  feet  allowing  no 


Fig.  80.- — Conventional  flow  sheet  of  a  continuous  counter-current  caus¬ 
ticizing  plant. 

room  for  operating.  Additional  tanks  for  weak  liquors  and  stor¬ 
age  or  mixing  of  cooking  liquor  must  be  provided  and  means  for 
the  final  disposition  of  the  sludge. 

The  building  should  be  of  good  height,  not  less  than  forty 
feet,  and  all  above  ground  to  secure  a  good  light,  ventilation  and 
drainage.  There  should  be  an  upper  enclosed  deck  or  gallery  to 
contain  the  causticizers  and  a  storage  of  lime  conveniently  lo¬ 
cated. 

These  tanks  must  all  be  equipped  with  agitators  and  power 
to  drive  *them.  It  would  probably  require  an  equipment  of  100 
h.p.  capacity  to  operate  such  a  system,  though  the  actual  power 
required  for  some  of  the  time  would  be  less.  It  would  require  at 
least  three  men  to  operate  this  part  of  the  plant. 

A  causticizing  plant  according  to  the  Dorr  System  is  built  in 
ten  ton  of  caustic  soda  units.  Each  unit  requires  a  floor  space 
75  feet  by  26  feet.  It  would  require  five  such  units  for  a  produc¬ 
tion  of  100  tons  of  poplar  pulp  daily.  This  would  call  for  a 
floor  space  of  75  feet  by  130  feet.  It  is  possible  to  reduce  this 
floor  space  by  using  the  tray  type  of  thickeners.  No  additional 
space  would  be  required  for  weak  liquors  since  the  counter  cur- 


THE  SODA  PROCESS 


169 

rent  system  provides  for  this,  and  no  pumps  other  than  the  small 
diaphragm  pumps  are  required.  The  total  power  required  for 
each  unit  is  5  h-P-  One  man  only  would  be  required  to  operate 
the  whole  five  unit  plant. 

In  a  system  where  a  filter  forms  an  essential  element,  the 
capacity  of  the  filter  must  be  the  basis.  Choosing  the  Kelly  press 
as  one  type,  two  single  units,  or  one  twin  unit,  would  be  required. 

The  floor  space  occupied  by  the  single  press  is  53^  by  23  feet 
each.  Additional  space  must  be  provided  for  tank  supplying 
the  presses,  for  pumps,  air  compressor  and  operation. 

The  presses  must  be  situated  at  an  elevation  which  will  permit 
of  automatically  discharging  the  cake  into  a  hopper  and  thence 
to  a  conveyor  beneath.  Probably  50  b.p.  and  two  men  would 
be  ample  to  operate. 

It  will  thus  be  seen  that  the  building  and  floor  space  for  such 
a  plant  would  be  relatively  small,  the  idea  being  to  make  complete 
separation  of  solids  and  liquids  by  forced  filtration  of  tbe  original 
liquor  rather  than  by  a  progressive  separation  by  dilution  of  the 
residue  which  requires  large  tank  capacity. 

The  rotary  continuous  filter  operating  on  strong  caustic  sludge 
would  receive  the  sludge  from  a  continuous  settling  tank  as  de¬ 
scribed  above.  Two  of  these  filters  would  be  required  and  should 
be  placed  with  their  discharge  sides  facing  each  other  so  that 
the  cake  may  pass  to  a  common  conveyor.  Filters  of  this  type  of 
suitable  capacity  occupy  a  space  8x8x8  feet  and  weigh  about 
11,000  pounds  each. 

The  filtering  drum  revolves  about  r.  p.  m.  The  only  power 
required  for  this  work  would  be  for  an  exhaust  pump  which 
would  act  as  a  blower  at  the  same  time,  and  for  the  conveyor. 
Practically  no  labor  is  required  as  the  process  is  automatically 
continuous. 

In  discussing  the  relative  merits  of  the  different  causticizing 
processes  used  in  soda  pulp  mills  and  their  efficiency  as  regards 
steam  consumption  and  alkali  accounted  for,  it  is  necessary  to 
form  some  basis  of  efficiency.  In  the  older  decantation  process, 
in  most  general  use,  time  and  capacity  are  the  principal  effi¬ 
ciency  factors. 

An  alkali  room  (causticizing  room)  having  ten  pans  (each 
of  such  capacity  that  when  charged  with  liquor,  causticized,  prop¬ 
erly  settled,  dmwn  off  and  mixed  with  a  properly  settled  first 
wash,  there  will  be  enough  liquor  for  two  digesters)  is  capable 
of  furnishing  liquor  enough  for  twenty  digesters  in  24  hours. 
In  other  words,  each  pan  should  be  allowed  24  hours  for  one 
complete  cycle  in  order  to  obtain  good  economical  results.  This 
will  allow  the  strong  and  first  wash  each  4^  hours  and  each  of 
the  other  three  washes  3  hours  to  settle  before  syphoning  off  the 
clear  liquor.  When  handled  in  this  way,  the  lime  sludge  dis¬ 
charged  will  contain  about  85  per  cent  weak  liquor  and  15  per 
cent  solids  by  volume,  or  68  per  cent  weak  liquor  and  32  per 


170  MODERN  PULP  AND  PAPER  MAKING 

cent  solids  by  weight.  The  loss  of  soda  in  this  sludge  discharge 
will  be  from  one-half  to  three-quarter  per  cent  of  the  total  soda 
used. 

Thorough  agitation  is  also  a  necessary  factor  in  causticizipg 
soda  efficiently.  If  the  agitator  shaft  is  provided  with  one  set 
of  wings  near  the  bottom,  it  should  make  at  least  30  r.  p.  m. ;  but 
provided  with  three  sets  of  wings  at  three  different  heights,  the 
speed  of  the  shaft  can  be  cut  to  16  to  18  r.  p.  m.  arid  give  equally 
good  results.  Of  two  mills  using  the  same  size  alkali  pans,  the 
same  quality  of  lime,  and  all  other  conditions  the  same,  excepting 
the  speed  of  the  agitator  shaft,  the  shaft  in  one  mill  made  20 
r.  p.  m.  and  in  the  other  30  r.  p.  m.,  with  the  result  that  the  former 
was  obliged  to  use  about  8  per  cent  more  lime  than  the  latter; 
and,  on  account  of  using  extra  lime  to  get  the  same  causticity,  6 
per  cent  less  liquor  was  syphoned  from  the  strong  pan  in  the  for¬ 
mer  mill,  after  allowing  tne  pans  to  settle  the  same  length  of  time. 

When  using  a  lime  containing  94  per  cent  active  calcium  ox¬ 
ide,  it  is  customary  to  use  from  550  to  600  pounds  of  lime  for 
each  1,000  pounds  of  sodium  carbonate  causticized,  in  order  to 
get  a  strong  liquor  having  92  per  cent  of  the  total  soda  causti¬ 
cized.  This  strong  liquor  when  mixed  with  a  first  wash  of  97 
per  cent  causticity,  will  furnish  liquor  of  about  94.5  per  cent  caus¬ 
ticity  for  the  digesters.  The  lime  when  slacking  in  the  pan  of 
liquor  heats  it  and  will  furnish  about  480  B.  t.  u.  per  lb.  or  268,800 
B.  t.  u.  for  every  1,000  pounds  of  sodium  carbonate  causticized. 
This  will  raise  the  temperature  of  the  liquor  about  30°  F.  If 
the  liquor  from  the  leachers  tests  160°  F.,  the  lime  added  will 
raise  the  temperature  to  190°  F.  so  that  it  is  only  necessary  to  add 
enough  steam  to  raise  the  temperature  27°  higher  to  reach  boil¬ 
ing  point.  It  is  only  necessary  to  boil  the  pan  of  liquor  about 
15  minutes,  when  the  agitation  is  good,  but  agitation  should  be 
continued  from  20  to  30  minutes  longer. 

The  influence  of  quality  of  lime  on  time  necessary  to  boil  the 
liquor  is  important.  The  calcium  oxide  content  of  a  lime,  as 
found  by  analysis,  veiy  often  comes  far  from  representing  the 
active  content  of  the  lime.  Samples  of  lime  with  a  total  calcium 
oxide  content  of  85  per  cent  have  shown  an  active  content  as 
low  as  72  per  cent.  The  principal  cause  for  the  difference  be¬ 
tween  the  actual  and  active  calcium  aside  from  that  present  as 
carbonate,  is  due  to  presence  of  an  excessive  amount  of  silica  and 
alumina  in  the  form  of  silicates,  which  has  been  fused  by  over¬ 
burning  in  the  kiln,  and  encloses  some  of  the  active  lime,  making, 
it  difficult  for  the  slacking  water  to  reach  it.  Lumps  of  this  lime 
will  stand  in  hot  water  as  long  as  25  minutes  without  breaking 
down,  while  a  lump  of  good  slacking  lime  will  break  down  com¬ 
pletely  in  about  one  minute.  It  will  be  found  advantageous  to 
make  a  rough  slacking  test  in  the  alkali  room,  when  a  car  of 
lime  appears  refractory;  and  if  it  requires  much  time  for  the 
lumps  to  break  down  better  results  can  be  obtained  by  boiling  the 


THE  SODA  PROCESS 


171 

pans  of  liquor  an  additional  half  hour.  By  the  old  process,  al¬ 
lowing  24  hours  for  one  complete  cycle,  eight  pounds  of  soda  ash 
can  be  causticized  per  cubic  foot  of  pan  capacity  in  24  hours. 
Many  soda  pulp  mills  have  increased  their  production  to  such  an 
extent  that  the  alkali  room  is  worked  far  beyond  its  capacity ;  and 
the  result  is  inefficient  operation  in  this  department.  The  original 
ten  pans  are  trying  to  do  the  work  of  fifteen,  which  results  in 
cutting  the  cycle  of  time  16  hours  in  place  of  24,  and  causing  a 
loss  of  from  3  per  cent  to  4  per  cent  of  the  total  soda  causticized. 

The  newer  processes  cannot  be  considered  substitutes  for  the 
causticizing  process,  as  the  first  step  in  the  operation  is  the  same 
in  every  case.  The  soda  ash  must  first  be  causticized  by  boiling 
with  lime.  It  is  from  this  point  on  that  improvements  have 
come  to  the  assistance  of  the  soda  pulp  manufacturer.  By  a  small 
addition  to  his  alkali  room  he  is  able  to  secure,  with  the  same 
number  of  pans,  an  increase  in  capacity  of  100  per  cent  to  150 
per  cent.  The  improvements  consist  in  new  methods  of  separat¬ 
ing  the  liquor  from  the  sludge  after  the  causticizing  process  is 
finished,  effecting  a  saving  of  time  and  space,  and  cutting  down 
the  loss  of  soda  in  the  sludge  discharges. 

Percentage  of  Recovery. 

Throughout  the  recovery  plant  in  a  soda  mill  everything  must 
be  reduced  to  standard  methods  and  accurate  records  must  be 
kept,  otherwise  there  is  sure  to  be  a  steady  loss  in  soda  which 
cannot  be  explained  by  any  one  factor.  Such  a  loss  is  usually 
the  sum  total  of  a  great  many  things  that  are  not  being  done  as 
they  should  be.  When  the  standard  amounts  of  liquor  or  water 
to  be  used  for  washing,  the  standard  time  for  washing,  etc.,  have 
been  worked  out  on  the  basis  of  tests  made  by  the  laboratory, 
strict  adherence  to  these  standards  should  be  insisted  on  and  a 
system  of  records  devised  to  show  how  well  the  system  is  work¬ 
ing  out.  Just  as  in  the  sulphite  process,  accurate  records  should 
be  kept  of  each  digester  cook.  Then  the  time  consumed  in  wash¬ 
ing  each  charge  in  the  washing  pans  should  be  recorded.  The 
records  of  the  evaporator  department  should  show  the  concen¬ 
tration  of  the  liquor  from  the  washing  pans,  the  density  and  tem¬ 
perature  of  the  concentrated  liquor  produced  (these  measure¬ 
ments  should  be  made  hourly)  and  the  pressure  maintained  on 
each  effect  of  the  evaporator.  The  concentration  and  temperature 
of  the  evaporated  liquor  should  not  vary  perceptibly  from  hour  to 
hour.  If  it  does,  a  thorough  investigation  should  be  made  of 
the  working  of  the  evaporator  system.  The  liquor  going  to  the 
rotary  furnaces  should  be  tested  several  times  each  day  and  the 
total  amount  of  this  liquor  should  be  known.  A  careful  record 
should  be  kept  of  the  amount  of  fresh  soda  added. 

In  making  up  the  liquor  for  use  in  the  digesters  a  hydrometer 
should  be  used  to  determine  whether  the  liquor  is  up  to  standard 
or  not,  and  the  degree  of  causticity  should  be  determined  by  the 


172  MODERN  PULP  AND  PAPER  MAKING 

laboratory.  The  help  in  the  alkali  room  can  easily  be  trained  to 
make  the  causticity  tests  which  can  be  checked  from  time 
to  time  by  the  chemist.  Needless  to  say,  the  digester  liquor 
must  be  absolutely  uniform.  If  abnormal  amounts  of  soda 
have  to  be  added  to  bring  the  liquor  up  to  strength  it  is  evi¬ 
dence  that  some  detail  of  the  recovery  system  is  not  in  proper 
working  order.  Although  the  operation  of  this  departmeiit 
should  be  checked  by  chemical  tests  in  the  laboratory  from  time 
to  time,  the  actual  work  is  done  by  men  who  must  be  instructed 
simply  in  terms  of  so  many  pounds  of  lime  and  soda  and  so 

many  inches  of  liquor.  -n  •  •  i 

To  calculate  the  percentage  of  recovery  m  the  mill  it  is  only 
necessary  to  know  the  number  of  pounds  of  soda  in  the  liquor 
charged  to  each  digester,  and  the  weight  of  new  soda  used  each 
day.  The  new  soda  added  is  deducted  from  the  total  soda  and 
in  this  way  the  percentage  of  recovery  worked  out. 

There  is  no  reason  why,  with  efficient  equipment  and  intelli¬ 
gent,  careful  supervision,  the  percentage  of  recovery  should  not 
be  ill  the  neighborhood  of  95  per  cent.  This,  however,  is  unusual 
and  the  writer  knows  of  two  mills,  which  are  usually  considered 
very  good  soda  mills,  where  the  management  is  satisfied  if  the 
percentage  of  recovery  exceeds  85  per  cent  although  it  frequently 
is  as  high  as  90.  Probably  the  average  throughout  the  country 
would  be  much  lower  than  this,  in  all  likelihood  not  higher  than  ^ 
75  or  80  per  cent.  The  chief  factors  which  make  the  actual  per-  ’ 
centage  recovery  lower  than  the  theoretical  are: — (i)  the  pulp 
is  not  washed  long  enough  or  carefully  enough  in  the  wash  pans ; 
(2)  the  draft  in  the  rotary  furnace  carries  away  some  soda  me¬ 
chanically  (modern  mills  are  installing  devices  to  recover  this 
soda)  ;  (3)  some  soda  is  left  in  the  lime  sludge  after  causticizing ; 
(4)  some  soda  is  retained  by  the  carbon  of  the  black  ash  through 
incomplete  washing;  (5)  poor  or  improperly  operated  evaporators 
will  allow  some  of  the  soda  liquor  to  escape  with  the  condensate; 
(6)  leaks,  spilling,  inaccurate  weighing  and  general  carelessness. 
It  is  usual  to  charge  all  losses  not  otherwise  explained  to  losses 
“up  the  stack.”  The  following  remarks  are  from  a  paper  on 
this  subject  by  George  K.  Spence.^ 

One  of  the  biggest  problems  confronting  the  soda  pulp  rnill 
superintendent  today  is  that  of  recovering  the  black  ash  passing 
out  of  the  rotary  stack. 

Some  have  tried  to  do  so  in  a  wet  way  by  spraying  the  stack 
with  weak  liquor  or  water,  but  so  many  products  of  combustion 
and  destructive  distillation  are  reclaimed  with  the  a.sh.  that  it 
forms  a  dirty  conglomerate  mass,  difficult  to  handle.  It  is  too 
dirty  to  send  to  the  leachers,  not  strong  enough  to  burn  without 
evaporation,  and  contains  too  much  suspended  solid  matter  to 
send  to  the  evaporators.  The  washing  has  been  accomplished 

’  Report  of  the  Committee  on  Soda  Pulp,  T.  A.  P.  P.  I.,  1919.  “Paper,”  Feb.  12, 
1919,  pg.  619. 


THE  SODA  PROCESS  173 

very  efficiently;  but,  as  stated  above,  it  has  been  a  very  difficult 
matter  to  prepare  the  resultant  liquor  for  use. 

Attempts  have_  been  made  to  separate  the  solids  from  the 
liquor  by  passing  it  through  a  plate  and  frame  filter  press ;  but 
this  process  is  very  slow  and  unprofitable.  We  give  below  a ’par¬ 
tial  analysis  of  solids  removed  by  the  press  and  the  liquor  from 
solids. 


Water  = 
Organic  \  _ 
Matter /  ~ 


54  65% 
19.22% 


Solids 


Mineral  \ 
Solids  / 


Water 
Organic  1 
Matter  / 


26.13% 


Insoluble . 

I  Sodium  Carbonate 
Sodium  Carbonate 
Sodium  Sulphate.  . 


Liquor 

72.23% 

9  64% 


1.00% 
23 -94% 
.688% 
•49% 


Mineral  1  _ 
Solids  /  ~ 


Insoluble .  =  .02% 

Sodium  Carbonate  =  12.41% 
Sodium  Chloride . .  =  1.90% 
,  Sodium  Sulphate .  .  =  2.51% 


A  centrifugal  apparatus  has  been  used,  and  the  resultant 
solids  and  liquors  showed  about  the  same  analysis  as  the  fore¬ 
going  ;  but  the  results  of  the  experiment  were  not  very  satis¬ 
factory.  It  does  not  seem  possible  to  reclaim  the  rotary  stack 
losses  satisfactorily  in  a  wet  way. 

There  have  been  several  methods  suggested  for  collecting  this 
dust  in  a  dry  way,  the  most  feasible  of  which  appears  to  be  the 
Cottrell  electrical  precipitation  process.  By  this  method  the  dry 
dust  is  collected,  while  the  moisture  and  gases  pass  out,  owing 
to  the  high  temperature  in  the  stack. 

_  This  is  an  expensive  installation  as  the  units  are  small,  re- 
quiring  360  collecting  electrode  pipes  15  feet  long  and  8  inches 
m  diameter  to  handle  50,000  cubic  feet  of  gas  per  minute.  More¬ 
over  special  generating,  transforming  and  controlling  equipment 
is  required.  The  operating  expenses,  including  interest,  depreci¬ 
ation,  royalty,  power,  labor,  etc.,  would  be  a  little  less  than 
$20,000  a  year  on  such  an  installation.  If  by  draught  control  it  is 
impossible  to  keep  the  stack  losses  below  7,000  lbs.  of  soda  a 
day  in  a  rotary  department  sending  50,000  cubic  feet  of  gas  per 
minute  up  the  stack,  it  is  advisable  to  use  this  or  some  other  dry 
dust  saving  system.  The  Cottrell  electrical  precipitation  system 
has  been  installed  in  the  rotary  department  of  several  pulp  mills. 

While  it  may  not  seem  advisable  to  install  an  expensive  sys¬ 
tem  to  reclaim  this  ash,  this  important  point  in  the  recovery  de¬ 
partment  should  not  be  overlooked.  It  should  be  under  efficient 
control  at  all  times,  and  the  speed  of  the  flow  of  gas  so  regulated 


174  MODERN  PULP  AND  PAPER  MAKING 

as  to  produce  the  best  burning  results,  with  the  smallest  possible 

loss  of  soda.  ,  , ,  ,  1  r 

In  order  to  determine  the  loss  of  black  ash  from  any  one  or 

from  all  rotaries,  it  is  necessary  to  pass  a  measured  volume  of 
gas  through  a  filtering  medium,  enclosed  in  a  sampling  tube,  ^tter 
which  the  volume  of  the  gas  is  reduced  to  dry  gas  at  standard 
conditions  (32°  F.  and  29.92  inches  of  mercury)  by  means  of  the 
following  formula:’ 

459  +  32  B-S-P 

V  =  V'  X  -  X  - - 

459  +T  29.92, 


V  =  volume  of  dry  gas  at  standard  conditions. 

V'  =  volume  of  gas  as  registered  on  meter. 

T  =  temperature  of  water  in  meter  in  degrees  Fahr. 

B  =  barometric  pressure  at  point  where  sample  is  taken. 

S  =  suction  in  inches  of  mercury  as  read  from  meter  gauge.  _ 

P  =  aqueous  tension  at  meter  temperature  (taken  from  psychrometnc  tables). 


From  this  corrected  volume  and  weight  of  dust  caught  m  the 
filter  the  amount  of  dust  per  cubic  foot  of  dry  standard  gas  can 
be  calculated.  By  means  of  the  wet  and  dry  bulb  readings  in 
the  flue  a  correction  is  made  for  the  aqueous  vapor  pressure  in 
order  to  bring  results  to  flue  conditions.  The  amount  of  soda  m 
the  dust  is  determined,  which  multiplied  by  the  volume  of  gas 
passing  through  the  flue,  will  give  the  amount  of  soda  lost  dur¬ 
ing  any  specified  time.  _  r  ..u  n 

It  is  first  necessary  to  take  a  Pitot  tube  traverse  of  the  flue 

in  order  to  determine  the  average  velocity  of  the  gas  throughout 

the  cross-section  of  same.  1  •  1  4.  1 

A  convenient  station  can  be  then  selected  at  which  to  take 

Pitot  tube  readings,  while  samples  are  being  taken,  and  use  a 
correction  factor  for  the  average  velocity.  For  example,  if  the 
average  velocity  is  21  feet  per  second,  and  the  station  selected 
showed  21.6  feet  per  second  when  the  traverse  was  taken  the  cor- 

21 

rection  factor  for  this  station  is  - =  .972,  which  should  be 

21.6 

used  to  multiply  all  succeeding  Pitot  tube  readings  by  in  order 
to  obtain  the  average  velocity  through  the  flue. 

The  velocity  of  the  gas  is  determined  by  means  of  the  follow¬ 
ing  formula  :  V  =  2.9  T.  H. 

V  =  velocity  of  the  gas  in  feet  per  second. 

T  =  absolute  temperature  in  degrees  Fahr. 

H  =  velocity  head  in  inches  of  water. 


The  volume  of  gas  passing  through  the  flue  is  determined  by 
multiplying  the  velocity  in  feet  per  minute  by  the  cross-sectional 
area  of  the  flue  in  square  feet,  giving  the  result  in  cubic  feet  ot 

gas  per  minute.  ,  .  ,  ,  ^  .. 

The  velocity  of  the  gas  entering  the  nozzle  of  the  dust  collec- 


r 


175 


THE  SODA  PROCESS 

tor  should  be  the  same  as  that  in  the  flue.  In  order  to  measure 
the  gas  at  the  proper  velocity  it  is  pulled  through  a  water  filled 
gas  meter  by  means  of  a  steam  or  an  air  syphon.  The  dust  can 
be  caught  in  paper  thimbles  when  the  temperature  is  under  450° 
F.  If  the  temperature  exceeds  this,  alundum  thimbles  should  be 
used. 

1.  — Meter  reading  in  cubic  feet. 

2.  — Temperature  of  water  in  meter  in  degrees  F. 

3.  — Suction  (negative  pressure)  on  meter  in  inches  of  mer¬ 
cury  as  shown  on  gauge. 

4.  — Temperature  of  gas  in  the  flue  in  degrees  F.  (with 
pyrometer). 

5- — Velocity  of  the  gas  in  the  flue  in  feet  per  second. 

6. — Static  pressure  in  the  flue  in  inches  of  mercury. 

7- — Wet  bulb  reading  in  the  flue  in  degrees  F. 

8.— -Dry  bulb  reading  in  the  flue  in  degrees  F. 

^  It  is  also  necessary  to  know  the  barometric  pressure  at  the 
point  where  the  sample  is  taken. 

By  tests  made  in  the  above  manner  it  has  been  found  that  14- 
foot  rotaries  lose  from  450  to  1,000  lbs.,  16-foot  rotaries  from  650 
to  1,300  lbs.,  and  30-foot  rotaries  from  2,500  to  4,000  lbs.  of  soda 
up  the  stack  in  twenty-four  hours. 

Many  varieties  of  dust  collecting  chambers  have  been  con¬ 
structed  between  the  rotary  and  the  stack,  some  of  which  are 
fairly  efficient;  but,  as  a  general  rule,  the  ash  collected  repre¬ 
sents  only  a  small  percentage  of  the  amount  of  ash  passing  up  the 
stack. 


IX.  The  Sulphate  Process. 

The  sulphate  process  is  a  modification  of  the  soda  process  in 
which  sulphate  of  soda  is  used  to  replace  soda  ash.  This  process 
was  invented  by  Dahl  in  Kurope  about  40  years  ago.  The 
Scandinavian  pulp  makers  were  finding  it  hard  to  sell  their 
soda  pulp  in  competition  with  the  then  recently  introduced  sul¬ 
phite  pulp  and  welcomed  the  sulphate  process  for  which  they 
obtained  sodium  sulphate  cheap  from  England,  where  it  was  a 
by-product  of  the  chemical  factories.  The  first  introduction  of 
the  sulphate  process  in  America  was  at  the  plant  of  the  Bromp- 
ton  Pulp  &  Paper  Co.  in  Canada  in  1907,  since  which  time  the 
industry  has  developed  rapidly,  the  U.  S.  and  Canada  today  pro¬ 
ducing  about  2,500  tons  per  day.  It  was  originally  used  for 
making  a  pulp  which  was  subsequently  bleached  yielding  a  very 
fine  grade  of  stock  from  which  excellent  soft  pliable  papers  suit¬ 
able  for  book  and  other  purposes,  could  be  made.  A  considerable 
amount  of  sulphate  pulp  is  still  prepared  which  is  subsequently 
bleached,  especially  in  Europe,  but  the  greatest  application  of 
the  sulphate  process  today  is  in  making  what  are  known  as 
Kraft  papers.  Kraft  paper  is  an  exceedingly  strong,  tough  paper, 
ideally  suited  for  wrappings  and  bags.  It  is  not  bleached,  haying 
a  natural  brown  color  which  is  characteristic  of  this  variety 
of  paper.  As  there  is  a  great  demand  for  this  product  and  as  a 
number  of  woods  can  be  reduced  to  pulp  by  this  process  much 
more  economically  than  by  any  other,  manufacture  of  Kraft 
paper  by  the  sulphate  process  has  assumed  very  large  propor¬ 
tions  in  the  paper  industry.  .  „ 

Originally  Kraft  paper  was  made  by  only  partially  digesting 
the  pulp  and  subsequently  completing  the  process  by  mechanical 
means  such  as  grinding  in  a  kollergang  or  edge-runner.  This 
procedure  required  a  great  deal  of  power  and  also  gave  a  very 
limited  output  as  the  capacity  of  the  kollergang  was  comparatively 
small.  In  the  modern  production  of  kraft  pulp,  the  cooking  is 
more  thorough,  and  the  subsequent  disintegration  of  the  pulp  is 
accomplished  in  the  beaters  and  Jordans. 

The  sulphate  process  costs  more  to  operate  than  the  soda 
process,  especially  as  concerns  the  recovery  system. 

The  Cooking  Liquor. 

Although  the  process  is  known  as  the  sulphate  process  be¬ 
cause  sodium  sulphate  is  used  in  making  up  the  liquor,  a  number 

176 


THE  SULPHATE  PROCESS 


177 

of  other  compounds  of  soda  are  present  in  the  liquor  as  used. 
The  liquor  as  actually  used  contains  in  solution : 

Sodium  Hydroxide  (NaOH) 

Sodium  Sulphide  (Na2S) 

Sodium  Carbonate  (Na2C03) 

Sodium  Sulphate  (Na2S04) 

The  actual  digestion  of  the  pulp  is  mainly  effected  by  the 
sodium  sulphide  in  the  liquor  and  it  has  been  suggested  that 
“sulphide  process”  would  be  a  more  correct  name  than  “sulphate 
process”  for  this  method  of  making  pulp.  A  high  percentage  of 
sulphate  or  carbonate  m  the  cooking  liquor  is  undesirable. 

Equipment. 

The  digesters  used  for  the  sulphate  process  are  practically 
identical  with  those  previously  described  in  connection  with  the 
soda  process.  They  must  be  well  insulated  to  avoid  heat  losses 
and  excessive  condensation.  Just  as  in  the  soda  process  no  spe¬ 
cial  lining  is, required,  such  as  is  used  in  the  sulphite  process,  be¬ 
cause  the  cooking  liquor  does  not  attack  the  metal  of  the  digester. 
Direct  cooking  such  as  is  used  in  the  sulphite  process  is  exten¬ 
sively  employed.  However,  recently  various  systems  of  indirect 
cooking,  the  digesters  being  equipped  with  a  system  of  forced  cir¬ 
culation,  have  been  successfully  applied.  The  Morterud  process, 
previously  described  in  connection  with  the  cooking  of  sulphite 
pulp,  is  typical  of  these  systems.  It  is  claimed  by  the  proprietors 
of  this  system  that  it  will  reduce  the  cooking  time  to  one-third 
of  that  required  by  the  direct  cook,  that  it  will  save  chemicals, 
and  that  it  will  render  the  evaporation  problem  in  the  recovery 
of  the  liquor  much  simpler,  owing  to  the  fact  that  in  the  indirect 
cooking  process  the  liquor  is  not  diluted  by  steam.  It  is  stated 
that  the  actual  saving  for  a  three-ton  digester  based  on  six 
cooks  daily  will  amount  to  1,500  tons  annually.  ^The  objection 
to  the  indirect  process  in  the  past  has  been  based  on  the  difficulty 
of  keeping  the  equipment  in  good  order.  Great  attention  has 
been  paid  to  the  details  of  the  design  of  the  heaters  and  pumps 
in  this  system  and  it  is  in  successful  operation  in  many  sul¬ 
phate  mills  today. 

Details  of  the  Process. 

The  wood  is  prepared  for  the  sulphate  process  exactly  as  for 
the  sulphite  process  excepting  that  it  is  frequently  not  considered 
necessary  to  exercise  such  extreme  care  to  eliminate  all  bark 
and  unsound  wood  as  is  desired  in  the  case  of  the  sulphite  process. 
This  is  because  the  cooking  liquor  used  in  the  sulphate  process 
will  dissolve  any  particles  of  bark  or  unsound  wood  and  they  will 
not  be  found  in  the  finished  pulp. 

The  above  remarks  should  not  be  interpreted  as  meaning  that 
unbarked  and  dirty  wood  can  be  used  in  the  sulphate  process  to 


178  MODERN  PULP  AND  PAPER  MAKING 

produce  the  best  quality  of  pulp.  The  wood  is  barked  for  use  in 
the  sulphate  process  just  as  in  the  sulphite,  but  the  extreme  care 
which  the  best  manufacturers  of  sulphite  pulp  use  to  prevent 
particles  of  bark  at  all  getting  into  the  digesters  is  not  necessary 
in  the  sulphate  process.  For  instance, 'if  a  block  happened  to  have 
a  few  shreds  of  bark  adhering  to  it  after  leaving  the  barking 
drum,  it  would  hardly  be  necessary  to  remove  this  bark  by  hand 
as  should  be  done  in  making  sulphite  pulp. 


Courtesy:  Swenson  Evaporator  Company,  Chicago,  III. 

Fig.  81. — The  interior  of  sulphate  mill  showing  digester,  diffusing  tanks 
and  evaporators  from  which  the  liquor  is  pumped  direct  to  the 
rotary  furnaces. 

The  wood  is  chipped  just  as  for  the  sulphite  process  and  the 
chips  stored  in  bins  from  which  they  are  run  into  the  digesters. 
After  the  required  amount  of  chips  has  been  placed  in  the  di¬ 
gester,  the  liquor  is  run  in  and  the  digester  closed.  The  pressure 
is  brought  up  to  20  or  25  pounds  at  which  point  the  cold  air 
present  in  the  charge  is  relieved.  Immediately  thereafter,  the 
pressure  is  brought  up  to  maximum  which  is  usually  about  100 
pounds  and  no  relieving  is  necessary  from  that  point  on  as,  unlike 
the  sulphite  cook,  no  gas  is  formed  during  the  cooking.  There 
is  no  top  pressure  and  the  temperature  and  pressure  will  corre¬ 
spond  right  up  to  the  end  of  the  cook. 

The  duration  of  the  cook  depends  on  the  quality  of  pulp  to 
be  produced  and  also  on  the  percentage  of  moisture  present  in 
the  wood,  and  other  factors.  From  2^  to  6  hours,  depending 
on  conditions,  is  usual ;  and  short  cooks,  say  MA'  hours,  jiredomi- 
nate.  When  the  cook  is  completed,  the  pulp  is  blown  into  the 
blow  pit,  just  as  in  the  sulphite  process.  In  making  the  sulphate 


Fig.  82. — Diagram  showing 
plan  and  elevation  of  recov¬ 
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179 


i8o  MODERN  PULP  AND  PAPER  MAKING 

pulp  it  is  customary  to  blow  the  digesters  at  a  somewhat  lower 
pressure  than  is  usually  the  case  with  sulphite  digesters.  This 
is  done  by  relieving  the  pressure  just  preliminary  to  the  blow.  It 
is  claimed  that  blowing  at  low  pressure  will  yield  a  better  quality 
of  pulp  in  addition  to  making  the  washing  of  the  pulp  in  the  blow 
pit  an  easier  matter. 

The  steam  blown  off  is  passed  through  a  separator  which 
eliminates  liquor  and  turpentine  which  is  always  formed  in  con¬ 
nection  with  this  process.  The  steam  is  used  to  heat  some  of  the 
water  used  in  washing  the  pulp. 

A  very  thorough  washing  is  necessary  for  this  class  of  pulp 


Courtesy :  Swenson  Evaporator  Company,  Chicago,  III. 


Fig.  83.— Recovery  equipment  being  installed  in  large  sulphate  mill.  The 
vertical  structures  in  the  background  are  waste  heat  boilers. 


not  only  to  give  a  pure  stock,  but  also  to  recover  the  highest  pos¬ 
sible  percentage  of  chemicals  used  in  the  process.  As  a  general 
rule  the  pulp  is  washed  in  series  of  diffusing  tanks.  The  dif¬ 
fusing  tanks  are  closed  as  the  vapors  given  off  in  the  sulphate 
process  are  malodorous  and  noxious.  In  the  first  of  these  tanks 
it  is  washed  with  waste  liquor  and  in  each  of  the  succeeding  ones 
with  more  and  more  dilute  liquor  until  it  is  finally  washed  with 
pure  water.  By  this  process,  the  percentage  of  soda  in  the  liquor 
is  systematically  concentrated. 

The  waste  liquors  all  go  to  a  recovery  system  and  the  efficient 
operation  of  this  recovery  system  is  the  most  important  detail  in 
connection  with  a  successful  operation  of  a  sulphate  mill. 

The  recovery  system  consists  of  evaporators  and  rotary  fur¬ 
naces  quite  similar  to  those  already  described  in  connection  with 


THE  SULPHATE  PROCESS  i8i 

the  soda  process.  Where  the  indirect  cook  is  used  multiple  effect 
evaporators  are  sometimes  dispensed  with,  the  liquor  being  suffi¬ 
ciently  concentrated  to  go  direct  to  the  disc  evaporators. 

However,  the  latter  stages  of  the  recovery  are  somewhat 
different  owing  to  sulphate  of  soda  being  substituted  for  soda  ash 
in  this  process.  The  black  ash  from  the  rotary  furnace  is  mixed 
with  sulphate  of  soda  and  sawdust  and  thrown  into  a  smelting 
furnace ^  lined  with  soapstone  (alberene  stone),  or  refrac¬ 
tory  brick.  Air  is  forced  into  the  furnace  and  the  black 
ash  is  burned,  during  which  operation  part  of  the  sulphate 
of  soda  is  reduced  to  sulphide  of  soda.  Some  carbonate  of  soda 


Courtesy:  Swenson  Evaporator  Company,  Chicago,  III. 


Fig.  84. — Part  of  recovery  system  in  sulphate  mill  showing  disc  evaporator 

and  waste  heat  boiler. 

is  also  produced  and  some  of  the  sulphate  of  soda  passed  through 
this  process  unaltered.  The  hot  gases  from  this  furnace  are  used 
to  heat  the  rotary  furnace  in  which  the  final  concentration  of  the 
waste  liquor  has  previously  taken  place.  The  fused  alkali  from 
the  smelting  furnace  runs  into  a  dissolving  tank  set  in  a  con¬ 
crete  pit  and  filled  with  an  agitator  where  it  is  dissolved  with  the 
proper  quantity  of  water  or  weak  liquor  from  the  washing  of 
the  lime  mud  in  the  causticizing  department.  It  is  then  pumped 
to  the  cauticizing  system.  The  causticizing  system  and  the  gen¬ 
eral  arrangements  for  preparing  the  liquor  for  charging  the  di¬ 
gester  are  not  materially  different  from  those  used  for  the  soda 
process. 

The  fresh  liquor  from  the  causticizing  department,  usually 
known  as  “white  liquor,”  is  generally  made  stronger  than  is  in- 


i82  modern  pulp  and  PAPER  MAKING 

tended  to  be  used  in  the  digesters,  and  is  subsequently  diluted 
with  black  liquor,  thus  making  up  the  volume  and  concentration 

required  for  the  digester.  ^  ,  n  -ru 

This  is  generally  done  with  tanks  provided  with  floats,  i  ne 
tanks  have  previously  been  calibrated,  i.  e.,  the  operator  knows 
how  many  gallons  are  represented  by  an  inch  of  height  on  the 

tank.  . 

The  composition  of  the  cooking  liquor  depends  on  many  tac- 

tors  such  as  the  nature  of  the  wood,  the  duration  of  the  cook. 


Courtesy:  Swenson  Evaporator  Co.,  Chicago,  III. 

Fig.  84a. — View  in  recovery  department  of  sulphate  mill  showing  leach¬ 
ing  tanks  and  discharge  end  of  smelting  furnace. 

etc.,  but  in  general  it  should  analyze  about  40  to  65  grams  per  liter 
of  caustic  soda  and  about  15  to  40  grams  per  liter  of  sodium  sul¬ 
phide.  The  total  amount  of  mixed  caustic  soda  and  sodium  sul¬ 
phide  will  be  about  16  to  23  pounds  per  100  pounds  of  wood  to 
be  pulped,  on  a  bone-dry  basis.  The  sulphate  and  the  carbonate 
should  be  kept  low  in  the  cooking  liquor,  as  neither  of  these  chem¬ 
icals  has  any  active  part  in  the  pulping  process.  The  sulphate  will 
be  high  if  the  reduction  in  the  smelting  furnace  is  not  properly 


THE  SULPHATE  PROCESS  183 

conducted.  Incomplete  causticization  is  the  chief  cause  of  an 
excess  of  carbonate.  Even  if  the  reduction  should  be  complete  in 
the  smelting  furnace,  there  will  be  some  sulphate  in  the  liquor  as 
sodium  sulphide  will  always  gradually  oxidize  to  sulphate  in  solu¬ 
tion.  In  actual  practice  the  liquor  contains  small  amounts  of 
many  other  compounds  of  sulphur  and  soda. 

The  success  or  failure  of  a  sulphate  mill  depends  largely  on 
the  efficiency  with  which  the  recovery  system  is  operated  and  very 
accurate  chemical  control  is  necessary  if  the  best  results  are  to  be 
obtained  in  this  department.  Much  that  has  been  written  on  this 
subject  relates  to  European  conditions  which  are  not  identical 
with  those  in  America  and  much  money  has  been  wasted  in  at¬ 
tempting  to  import  Scandinavian  sulphate  practice  bodily  to  this 
continent.^  New  and  improved  methods  of  recovery  are  con¬ 
stantly  being  devised  by  American  chemical  engineers  and  evap¬ 
orator  builders  which  are  based  on  actual  knowledge  of  Ameri¬ 
can  conditions.  Any  of  our  readers  who  wish  to  go  into  detail 
on  this  subject  would  be  interested  in  the  bulletins  issued  by  the 
Swenson  Evaporator  Co.,  Chicago,  also  in  a  paper  by  Hugh 
K.  Moore,  published  in  “Chemical  and  Metallurgical  Engineer¬ 
ing,”  August  I,  1917,  pages  117  to  125.  In  this  paper,  Mr. 
Moore  outlines  the  drawbacks  of  the  recovery  process  for  sul¬ 
phate  mills  as  ordinarily  operated  and  describes  various  improve¬ 
ments  which  he  introduced  in  remodeling  a  large  sulphate  mill 
in  Canada.  The  ideas  advanced  in  this  paper  are  very  novel 
as  the  author  does  not  hesitate  to  depart  radically  from  the  pre¬ 
viously  established  systems  in  plants  of  this  kind.  However,  his 
proposals  seem  to  have  worked  out  well  in  practice  and  the  article 
makes  profitable  reading  for  any  one  interested  in  this  particular 
branch  of  the  paper  industry.  It  is,  however,  doubtful  if  sulphate 
mills  in  general  will  abandon,  as  Mr.  Moore  has  done,  tested 
methods  until  the  newer  practice  has  been  in  use  long  enough  for 
its  own  shortcomings  to  become  apparent. 


X.  The  Ground  Wood  Mill. 

Ground  wood  pulp  constitutes  the  lowest  class  of  pulp  because 
of  the,  inferior  strength,  length  and  stiffness  of  its  fibre.  As  a 
result  of  these  characteristics  it  is  almost  impossible  to  obtain  a 
sufficiently  strong  sheet’  on  the  machine  by  the  use  of  ground 
wood  pulp  alone,  but  it  has,  when  mixed  with  a  certain  percentage 
of  chemical  pulp,  a  wide  application  in  the  manufacture  of  paper. 

Making  ground  wood,  as  the  term  implies,  is  purely^  a  me¬ 
chanical  process — the  essential  feature  of  the  process  being  the 
placing  of  a  log  under  pressure  against  the  surface  of  a  revolving 
stone.  There  are,  however,  some  slight  modifications  of  this 
process,  the  products  of  which  are  called  semi-chemical  pulps, 
wherein  wood  before  being  ground  is  submitted  to  a  steam  treat- 
'ment. 

There  are  many  items  to  be  considered  in  the  manufacture  of 
ground  wood  the  most  important  of  which  are:  (i)  Power;  (2) 
Quality  of  wood;  (3)  Preparation  and  handling  of  wood;  (4) 
Burring  of  the  stones;  (5)  Temperature  and  pressure;  (6)  Speed 
of  stone;  (7)  Organization;  (8)  Good  mechanical  equipment. 

Power. 

Ground  wood  mills  are  ordinarily  located  where  there  is  plenty 
of  available  water  power;  otherwise  steam  or  electric  power  is 
used.  Up  to  within  a  few  years  ago  practically  all  pulp  grinders 
and  other  motive  power  for  running  screens  and  presses,  etc., 
was  supplied  by  water  wheels,  but  today  the  motor  driven  ground 
wood  mill  is  finding  an  increased  field.  In  this  branch  of  the  in¬ 
dustry  the  total  horse  power  used  has  grown  from  10,000  to  some¬ 
thing  around  70,000  and  this  figure  is  steadily  increasing  as 
manufacturers  are  beginning  to  realize  the  efficiency  of  motor 
driven  grinders.  If  sufficient  water  power  were  available  the 
year  round  there  would  be  no  necessity  for  motor  driven  grinders, 
but  it  is  due  to  the  fact  that  uniform  water  power  is  not  always 
available  that  the  water  wheel  is  being  supplemented  by  the 
motor.  When  water  is  low  a  certain  number  of  grinders  or  of 
pockets  are  withdrawn  to  lessen  the  load.  Some  rnills  find  it 
necessary  to  make  all  of  their  ground  wood  pulp  during  that  pe¬ 
riod  of  the  year  when  water  power  is  uniformly  available,  but 
this  handicaps  other  operations  at  such  times  when  the  ground 
wood  mill  is  not  in  operation ;  for  during  these  times  the  paper 
mill  constantly  calls  for  a  variation  of  free  and  slow  stock  which 
cannot  be  supplied  by  the  ground  wood  mill  as  a  result  of  insuffi¬ 
cient  water  power. 


184 


THE  GROUND  WOOD  MILL  185 

Quality  of  Wood. 

The  quality  of  mechanical  pulp  is  determined  to  a  large  extent 
by  the  texture  of  the  wood,  the  age  and  the  seasoning.  Wood 
for  grinding  must  be  sound,  that  is  to  say,  the  interior  must  not 
be  reddened  by  disease,  neither  blue  nor  black  owing  to  the  felled 
trees  being  left  too  long  exposed  to  the  damp  air.  The  moisture 
in  the  air  permits  slow  decomposition  of  the  ligneous  fibres,  at¬ 
tracts  insects,  and  develops  mould. 

The  best  wood  is  that  which,  after  the  trees  have  been  felled, 
has  been  preserved  on  a  dry  and  very  airy  spot,  stacked  consecu¬ 
tively  so  as  to  allow  active  circulation  of  air,  and  which  is  used 


Courtesy The  Pnsey  and  Jones  Co.,  Wilmington,  Del, 

Fig-  85. - Typical  pulp  grinder. 


within  six  to  twelve  months  after  cutting.  The  fresher  and 
greener  the  wood  the  more  easily  will  it  grind,  the  yield  will  be 
higher  and  less  power  will  be  consumed.  It  is  more  difficult  to 
secure  a  long,  free  stock  from  wood  that  is  dried  and  has  been 
seasoned  than  from  good  fresh  material.  Pitchy  wood  should 
not  be  used  for  making  ground  wood  pulp  unless  previously 
treated  by  steam. 

Equipment. 

The  equipment  of  the  ground  wood  mill  includes  grinders  of 
various  types,  all  of  which  are  efficient  under  proper  management. 


i86  MODERN  PULP  AND  PAPER  MAKING 

grind  stones  with  proper  burring  facilities,  silver  screens,  stock 
and  pressure  pumps,  pulp  screens,  flow  boxes,  wet  machines,  stock 
tanks  and  hydraulic  presses.  We  must  also  include  generators 
whether  they  are  run  by  water,  steam  or  electricity.  With  the 
above  equipment  and  with  intelligent  supervision  ground  wood 
pulp  can  be  economically  and  efficiently  made. 

Grinders:  The  type  of  grinder  universally  used  consists  of 
a  large  grindstone  usually  about  54  inches  in  diameter^  and  wide 
enough  to  accommodate  i6-inch  or  .  24-inch  blocks.  There  are 


Courtesy:  IVaterous  hngtne  Works  Co.,  Ltd.,  tsrantfora,  unt. 

Fig.  86.— Battery  of  grinders  being  installed  in  ground  wood  mill. 


some  grindstones  in  operation  that  are  54  inches  wide  which  ac¬ 
commodate  4-foot  wood.  The  grindstone  is  mounted  on  a  shaft 
and  revolves  inside  an  iron  casing  which  usually  has  three  com- 
''partments.  At  the  upper  extremity  of  each  of  these  compart¬ 
ments  are  hydraulic  cylinders  fitted  with  piston  heads  and  as  the 
wood  is  fed  into  the  compartment  the  head  forces  the  wood 
against  the  revolving  stone.  The  pressure  is  furnished  by  either 
a  close  fitted  centrifugal  pump  or  a  duplex  or  triplex  plunger 
pump.  The  pump  is  usually  driven  from  the  grinder  spindle. 
The  friction  between  the  stone  and  the  wood  causes  an  intense 
heat  which  necessitates  the  use  of  a  large  stream  of  water  the 
object  of  which  is  to  clear  the  stone  and  also  reduce  the  tempera¬ 
ture  of  the  operation.  Failure  to  keep  the  temperature .  suffi¬ 
ciently  low  causes  the  stone  to  become  glazed  and  the  stock  is 
burned  lifeless  and  short.  The  capacity  of  the  grinder  depends 


THE  GROUND  WOOD  MILL  187 

on  the  nature  of  the  wood  and  the  power  available,  but  it  usually 
runs  from  two  tons  to  seven  tons  per  24  hours  and  requires  ap¬ 
proximately  200  to  600  h.p.  per  grinder. 

As  the  ground  wood  pulp  reaches  the  grinder  pit,  it  falls  to 
the  silver  screens,  a  series  of  iron  plates  perforated  with  ^-inch 
or  _i4-inch  holes  that  remove  the  larger  bull  slivers,  knots  etc 
which  are  carried  off  from  the  surface  of  the  screens  by  a  dra^ 
conveyor,  dumping  the  bull  slivers  in  a  receptacle  at  the  top  of 
Its  course.  The  screen  and  conveyor  is  constantly  showered 
with  water  to  wash  off  any  fibres  adhering  to  the  large  slivers. 

1  nese  bull  chips  are  in  turn  sent  to  a  sliver  grinder  or  else  burned 
as  fuel  m  the  boiler  house.  Either  flat  or  rotary  screens  can 
be  efficiently  used  for  the  removal  of  these  large  bull  slivers. 

The  stock  freed  from  these  large  slivers  is  pumped  to  a 
centrifugal  or  diaphragm  pulp  screen,  which  removes  the  last 
traces  of  slivers  and  coarse  stock.  This  stock  pump  is  either  a 
slow  speed  fan  pump  or  a  plunger  type  pump.  It  is  very  good 
practice  to  design  the  pipe  suction  from  sliver  screen  to  suction 
of  pump  of  ample  size  to  handle  stock  without  unnecessary  fric¬ 
tion.  An  8-inch  fan  pump  will  handle  the  stock  from  four 
3-pocket  grinders  under  ordinary  conditions  and  will  pump  the 
stock  to  the  screens  with  approximately  20  h.p.  This  figure  is 
for  a  stock  line  of  8  inches  diameter  and  approximately  130 
feet  in  length.  Through  these  screens  only  the  finest  fibres  are 
permitted  to  pass,  the  rejected  coarser  particles  being  passed 
through  a  Jordan  or  some  other  machine  for  reducing  and  re¬ 
fining  them,  after  which  they  are  again  passed  over  the  screens, 
i  he  construction  and  operation  of  these  screens  is  described  in 
detail  elsewhere. 

At  this  point  in  the  process  the  consistency  of  the  stock  is 
about  one-half  of  i  per  cent,  as  a  large  amount  of  water  is  re¬ 
quired  for  disintegrating  and  washing  and  screening— approxi¬ 
mately  150,000  gallons  of  water  per  ton  of  air  dry  product. 

The  removal  of  a  certain  percentage  of  water  from  this  very 
dilute  mixture  is  ordinarily  performed  by  means  of  a  pulp  thick¬ 
ener  which  IS  a  cylinder  revolving  in  a  vat  of  stock,  the  cylinder 
being  fitted  with  a  wire  netting  of  about  six  meshes  to  the  inch 
which  supports  a  finer  wire  cloth.  The  top  of  the  cylinder  is 
above  the  contents  of  the  vat  and  as  it  revolves  the  water  passes 
through  to  the  inside  and  leaves  a  thin  layer  of  pulp  on  the  outside. 
At  this  point  the  machine  resolves  itself  into  either  one  of  two 
types  depending  on  whether  deckered  stock  or  pressed  stock  is  to 
be  made.  If  stock  is  to  be  used  in  the  mill  direct,  it  can  be 
scraped  off  from  the  top  of  the  cylinder  with  a  doctor  and  then 
pumped  to  the  beater  as  required.  This  operation  is  that  of 
deckering  while  the  machine  consisting  of  vat,  revolving  cylinder 
and  doctor  for  removing  the  stock  is  termed  a  decker.  The  other 
type  IS  that  of  the  wet  machine  or  press.  This  has  already  been 
described  m  the  chapter  on  the  sulphite  mill.  Where  the  paper 


i88  MODERN  PULP  AND  PAPER  MAKING 

mill  is  isolated  from  the  pulp  mill  the  stock  is  prepared  in  this 

lap  form.  ■  j 

Under  ordinary  conditions  where  stock  is  to  be  shipped  to  a 
short  distance  the  ordinary  wet  press  previously  described  gives 
a  lap  of  stock  sufficiently  dry  for  transportation.  From  an 
economical  standpoint  where  stock  must  be  shipped  a  long  dis¬ 
tance  it  is  advisable  to  submit  the  laps  from  the  regular  wet  press 
to  the  action  of  a  hydraulic  press  which  leaves  only  40  per  cent 
of  water  in  the  stock.  There  are  theories  to  the  effect  that  pulp 
containing  70  per  cent  moisture  will  not  decay  as  rapidly  as  the 
hydraulically  pressed  pulp.  In  the  case  of  a  law  test  pulp  when  a 
certain  amount  is  piled,  the  weight  exerted  presses  the  air  put  and 
results  in  the  canning  of  the  pulp,  leaving  a  wet  mass  which  pre¬ 
serves  the  ground  wood  just  as  wood  which  has  been  sunk  in  a 
river  is  preserved. 

Water  Supply. 

The  water  supply  for  the  ground  wood  mill  is  usually  fur¬ 
nished  by  a  pressure  pump  of  either  centrifugal  or  plunger  type. 
The  water  is  taken  from  a  water  screen  of  revolving  cylinder 
type,  the  size  commonly  used  being  42  inches  diameter  by  84 
inches  long,  the  capacity  of  this  size  being  750,000  gallons  for  24 
hours.  This  size  will  supply  a  4-grinder  rnill  of  approximately 
8  ton  capacity  and  will  require  12  h.p.  to  drive  both  water  screen 
and  pump,  provided  the  pump  is  not  pumping  against  a^  head 
greater  than  50  feet,  and  through  a  discharge  pipe  of  8  inches 
diameter,  with  10  inches  suction  on  the  pump. 

Operation  of  the  Ground  Wood  Mill. 

In  the  manufacture  of  ground  wood  pulp  one  of  the  most 
essential  factors,  so  far  as  cost  is  concerned,  is  that  of  handling 
the  raw  material.  All  modern  plants  have  studied  this  question 
and  have  arranged  their  plants  so  that  waste  of  material  aiid  un¬ 
necessary  handling  of  material  shall  be  reduced  to  a  minimum, 
since  the  raw  material  itself  is  the  most  expensive  item.  The 
wood  in  its  course  from  the  wood  yard  through  the  mill  up  to  the 
grinders  should  not  be  touched  by  hand  but  should  be  conveyed 
by  a  system  of  conveyors  that  will  eliminate  costly  hand  manipu¬ 
lation. 

The  question  of  barking  and  cutting  and  preparing  the  wood 
has  already  been  taken  up  in  the  chapters  on  the  sawmill  and  the 
wood  room  and  therefore  calls  for  no  further  discussion. 

Burring:  Closely  allied  in  importance  to  the  choice  of  raw 
materials  is  the  question  of  the  burring  of  the  stones  as  the  sur¬ 
face  of  the  pulp  stones  has  an  extremely  important  effect  upon 
both  the  quality  and  the  quantity  of  pulp,  that  the  grinder  will 
produce.  Stones  suitable  for  grinding  pulp  for  wall  board  and 
various  bag  papers  would  not  be  suitable  for  making  a  light 
weight  Manila  sheet  containing  from  40  to  60  per  cent  of  ground 


THH  GROUND  JVOOP  MILL 


189 


wood.  1  his  necessitates,  consequently,  tlie  selecting  of  grind- 
stones  properly  surfaced  for  the  particular  gratle  of  pulp  desired. 
A  coaise  stone  should  be  used  for  coarse  pulp  while  a  stone  with 
a  finer  grit  should  be  used  for  fine  pulp.  Since  stones  vary  in 
texture  to  a  large  extent,  these  natural  variations  must  be  regu¬ 
lated  by  proper  burring  of  their  surface  so  that  this  irregularity 
will  not  shpw  up  in  the  finished  pulp. 

The  object  of  burring  is  to  expose  new  sharp  particles  of  grit 
and  at  the  same  time  provide  depressions  in  the  stone  The 
operation  is  performed  by  means  of  a  burr  placed  against  the  re¬ 
volving  stone.  There  are  many  different  types  of  burrs  on  tbe 
market^  all  of  which  differ  slightly  in  pattern  on  the  outside  cir¬ 
cular  circumference.  Tests  have  been  made  which  show  that  if 
two  types  of  burr  are  taken  and  tbe  stones  ground  to  the  same 


Fig.  87. — Two  typical  forms  of  burr. 


depth  in  each  case,  the  resulting  product  will  be  similar  indicat¬ 
ing  that  if  the  stone  is  properly  dressed  the  product  will  be  good, 
regardless  of  the  type  of  burr.  However,  there  are  some  types 
of  burr  whereby  it  is  easier  to  maintain  a  desired  surface  and 
which  eliminate  a  large  amount  of  the  personal  element  in  so  far 
as  dressing  is  concerned. 

There  are  many  different  conditions  that  influence  the  burring, 
tor  instance,  whether  the  burr  is  held  at  one  arm  of  the  lever  and 
ted  across  the  stone  by  hand  or  whether  it  is  held  by  tool  posts 
and  automatically  fed  across  the  stone  by  a  screw  device,  where 
the  pressure  of  the  burr  against  the  stone  is  entirely  a  matter  of 
the  operator’s  judgment. 

When  the  grinder  pressure  and  speed  are  held  constant  the 
ettect  of  sharpening  the  pulp  stone  is  to  increase  the  production 
and  produce  a  pulp  of  a  coarser  quality. 

_  Influence  of  Temperature:  Temperature  conditions  greatlv 
influ^ence  the  quality  o{  the  final  product.  The  pulp  of  most  value 
o  t  e  paper  maker  is  that  which  has  the  best  felting"  properties. 


190  MODERN  PULP  AND  PAPER  MAKING 

To  obtain  this,  the  pulp,  should  not  be  ground  too  cold,  for  under 
these  conditions  the  stones  are  kept  clear  of  pulp  and  have  a 
much  greater  cutting  action,  resulting  in  pulp  that  consists  of 
small  bundles  of  fibres  instead  of  single  fibres.  This  causes 
it  to  have  no  felting  properties.  On  the  other  hand  grinding 
pulp  too  hot  results  in  the  so-called  worthless  flour  pulp,  which 
is  of  no  value  to  the  paper  maker  as  the  fibres  are  practically 
dead  and  inert.  Too  hot  grinding  also  causes  an  excessive  wear 
on  the  surface  of  the  stone. 


Fig.  88. — Diagram  showing  construction  of  a  typical  automatic  burr. 

It  has  been  found  that  a  temperature  of  140°  F.  is  a  good 
average  temperature  at  which  to  obtain  a  mechanical  \vood  pulp 
approaching  as  nearly  as  possible  the  quality  of  a  chemical  wood 
pulp. 

Pressure:  Other  variables  remaining  constant,  the  produc¬ 
tion  varies  directly  with  the  cylinder  pressure.  The  quality  of 
the  pulp  is  determined  by  the  unit  pressure  with  which  the  wood 
is  forced  against  the  surface  of  the  stone.  In  grinding  a  round 
stick  ten  inches  in  diameter,  the  pressure  on  the  stone  will  be 
one-tenth  as  great  when  the  greatest  diameter  is  reached  as  when 
the  stick  presented  a  width  of  one  inch  near  the  beginning  of 


THE  GROUND  WOOD  MILL  191 

the  operation,  with  the  ultimate  result  that  the  product  contains  a 
mixture  of  fibres  produced  under  a  continuous  change  of  unit 
pressure. 

The  speed  of  the  pulp  stone  has  a  greater  influence  on  pro¬ 
duction  than  upon  the  actual  quality  of  the  stock  itself,  in  that 
the  production  increases  directly  with  the  peripheral  speed.  But 
in  dectrically  driven  installations  the  fluctuation  is  very  slight. 
This  variation  in  speed  applies  more  to  water  driven  units. 

In  the  production  of  mechanical  pulp  the  human  element  is  an 
important  factor.  As  a  result  of  the  slight  readjustment  of 
pressure,  temperature,  speed  and  burring  the  slightest  change  of 
workmanship  from  man  to  man  will  have  its  effect  not  only  on 
quality  but  on  production.  Within  certain  limits  this  factor  can 
be  controlled  by  careful  supervision,  by  periodical  checks  on  the 
mill  s  operations.  It  is  a  well  established  fact  that  production 
will  be  lowered  during  night  shifts  which  is  easily  accounted  for. 
The  decrease  is  caused  by  the  manner  in  which  the  pulp  wood  is 
fed  into  the  cells  of  the  grinder.  This  can  be  so  arranged  that  a 
block  can  be  wedged  between  two  others,  producing  a  resultant 
of  pressure  on  the  perpendicular  sides  of  the  pocket  instead  of 
transmitting  the  pressure  to  the  stone.  The  stick  does  not  grind 
away  so  fast  and  the  operator  gets  a,  chance  to  take  a  rest.  Such 
factors  cause  many  times  decreased  production  as  a  result  of  in¬ 
efficient  workmanship  and  lack  of  supervision. 

Between  the  power  from  the  motors  or  waterwheels,  condi¬ 
tion  of  stone  surface,  cylinder  pressure,  speed  of  stone  and  the 
human  factor  there  is  a  very  intimate  relation.  None  can  be 
altered  without  having  an  effect  upon  the  others. 

In  ground  wood  mills  operated  by  water  power,  when  the 
speed  of  the  stones  rises  too  high  production  suffers.  Some  of 
the  most  frequent  causes  for  a  rise  in  speed  are  (i)  binding  of 
the  wood  on  the  sides  of  the  wood  compartments,  (2)  withdrawal 
of  pressure  from  one  or  more  grinder  cylinders,  (3)  not  replen¬ 
ishing  a  pocket  immediately  after  it  has  become  empty  of  wood, 
(4)  drop  in  pressure  in  the  pump  line,  and  (5)  freshly  sharpened 
stones.  It  will  be  observed  that  many  of  these  causes  can  be 
traced  directly  to  the  operator. 

The  quality  can  be  controlled  within  certain  limits  for  different 
degrees  of  sharpness  of  stone  by  manipulating  the  cylinder  pres¬ 
sure  and  using  lower  pressures  on  a  sharp  stone  and  higher  ones 
on  a  dull  stone.  Lowering  the  cylinder  pressure  for  sharp  stones 
causes  the  speed  to  rise  and  if  the  gate  opening  is  decreased  pro¬ 
duction  suffers  excessively.  Increasing  the  pressure  with  a  view 
to  increase  production  requires  an  increase  in  power  delivered  to 
the  pulp  stone  in  which  case  all  of  the  installation  may  not  be 
operated. 

Grinders  have  been  developed  with  specially  adapted  pockets 
to  eliminate  the  binding  which  is  one  of  the  causes  of  rise  in  speed 
and  loss  in  production,  but  apparently  did  not  meet  with  any 


192  MODERN  PULP  AND  PAPER  MAKING 

marked  success.  Centrifugal  pumps  have  been  belted  to  grinder 
shafts  in  order  to  increase  the  cylinder  pressure  with  rise  in  speed 
of  the  stone  and  in  this  manner  restore  the  speed  to  normal. 
Their  action  is  rather  sluggish,  beside  producing  large  variations 
in  pressure  which  decreases  the  uniformity  of  the  pulp.  Gover¬ 
nors  attached  to  the  grinder  shaft  control  the  speed  successfully 
but  do  not  permit  the  water  wheels  to  operate  at  maximum  ca¬ 
pacity,  since  the  cause  of  the  decreased  load  is  not  removed,  and 
the  grinderman  can  not  readily  notice  faulty  performance.  Re¬ 
lief  valves  at  the  pressure  line  at  each  grinder  permit  adjust¬ 
ments  of  cylinder  pressure  to  keep  the  turbines  properly  loaded 
but  require  considerable  attention. 

As  a  means  of  controlling  the  speed  between  fairly  narrow 
limits  the  method  of  using  fewer  than  the  total  number  of  pockets 
on  any  line  of  grinders  should  give  good  results.  By  this  method 
the  surplus  pockets  are  kept  filled  with  wood  to  which  the  pres¬ 
sure  is  applied  when  the  load  is  withdrawn  from  other  pockets 
for  purposes  of  replenishing  or  rearranging  the  wood.  The  pe¬ 
riod  of  increased  speed  ordinarily  accompanying  these  latter 
operations  is  eliminated,  and  at  all  times  a  maximum  load  may  be 
maintained  upon  the  turbines. 

The  control  over  speed  should  be  primarily  to  maintain  pro¬ 
duction,  while  quality  is  probably  best  controlled  by  the  condition 
of  the  surface  of  the  pulp  stone.  It  has  been  pointed  out  that 
the  dressing  or  burring  of  the  pulp  stone  involves  to  a  very  great 
extent  the  human  factor,  and  does  not  permit  an  exact  duplica¬ 
tion  of  treatment. 

Each  superintendent  or  manager  has  his  own  theories  about 
the  method  of  grinding,  and  as  a  result,  scarcely  any  two  mills 
operate  under  the  same  conditions,  even  when  grinding  the  same 
species  and  turning  out  similar  products. 

For  example,  one  mill  producing  newspaper  has  135  h.p.  ap¬ 
plied  to  each  grinder;  the  pressure  computed  to  the  basis  of  a 
14-inch  cylinder  is  17.5  lbs.  per  square  inch,  and  the  peripheral 
speed  of  the  stone  is  2,660  feet  a.  minute.  In  another  mill,  with 
the  same  size  installation  and  making  the  same  class  of  paper, 
each  grinder  has  625  h.p.  applied  to  it,  uses  a  pressure  of  72  lbs. 
on  a  14-inch  cylinder,  and  a  peripheral  speed  of  3,540  feet  a  min¬ 
ute.  A  variation  of  from  135  h.p.  to  625  h.p.  to  the  grinders  is 
seen  in  the  example  cited. 

Reports  of  power  consumption  per  ton  of  pulp  in  twenty-four 
hours  show  a  range  of  from  65  to  100  h.p.  In  view  of  the  ex¬ 
treme  variation  in  the  conditions  of  manufacturing  mechanical 
pulp,  it  is  no  doubt  true  that  some  mills  are  operating  under  con¬ 
ditions  of  very  low  efficiency.  From  experiments  it  has  been  de¬ 
termined  that  the  utilization  of  a  considerable  amount  of  power 
is  necessary  to  obtain  a  strong  paper.  It  has  been  noted,  how¬ 
ever,  that  paper  increases  in  strength  with  the  power  consump¬ 
tion  only  up  to  a  certain  value ;  above  this  value  the  strength 


Tl^E  GROUND  WOOD  MILL 


193  - 


will  decrease.  Maximum  efficiency  in  the  production  of  a  mixed 
ground  wood  and  sulphite  paper  of  a  given  strength  requires  the 
proper  adjustment  of  both  the  power  consumption  of  the  grinder 
and  the  percentage  of  sulphite  in  the  mixture.  For  instance,  it 
might  be  desirable  to  use  a  small  amount  of  power  per  ton  of  pulp 
and  a  relatively  high  proportion  of  sulphite,  rather  than  a  higher 
power  consumption  and  lower  proportion  of  sulphite.  The 
proper  adjustment  would  depend,  of  course,  on  the  relative  value 
of  ground  wood  produced  by  high  and  lower  power,  and  sulphite 
fibre. 

In  electrically  driven  mills  many  attempts  have  been  made  to 
control  the  pressure  in  the  cylinders  of  the  grinders  so  that  nearly 
constant  full  load  would  be  carried  by  the  motor.  This  is  desir¬ 
able,  of  course,  from  an  electrical  standpoint,  because  by  holding 
constant  full  load  on  an  electric  motor,  advantage  is  taken  of  its 
highest  operating  efficiency.  Furthermore,  it  will  be  readily  ap¬ 
preciated  that  by  maintaining  conditions  at  their  full  load  value, 
the  output  of  ground  wood  will  be  very  much  increased  over  a 
condition  where  the  load  falls  below  normal. 

The  earliest  form  of  regulation,  consisting  of  belting  the 
pressure  pump  to  the  shaft  of  the  grinder,  so  that  when  the 
grinder  increased  its  speed  the  pump  would  do  likewise  and 
deliver  a  greater  pressure  on  the  cylinder,  thereby  reducing  the 
speed  of  the  revolving  grindstone,  is  useless  on  an  electrically 
driven  grinder,  since  the  motor  speed  is  practically  constant. 

A  form  of  regulation  better  adapted  to  electrical  installations 
consisted  of  a  throttle  operated  by  the  grinder  man,  who,  be¬ 
tween  his  duties  of  filling  the  pockets  with  wood,  was  supposed 
to  watch  an  indicating  meter  and  adjust  the  pressure  according  to 
the  load  as  shown  by  the  meter.  This  method,  however,  had  its 
shortcomings,  for  a  heavy  load  would  always  seem  to  appear 
when  the  grinder  man  was  otherwise  occupied. 

Electrical  Pressure  Regulators. 

Other  systems  of  regulation  have  been  tried,  among  which  is 
a  solenoid  connected  to  the  throttle  valve  so  fluctuations  of  load 
on  the  motor  would  actuate  the  solenoid  and  raise  or  lower  the 
valve  stem.  It  was  found  that  regulation  was  not  very  close  and 
fluctuations  in  the  water  system  would  occur  with  such  rapidity 
as  to  cause  a  pumping  action  and  inability  to  control  the  load  with 
any  degree  of  reliability  or  accuracy.  This  would  cause  excessive 
peaks  and  high  power  cost,  particularly  where  power  is  purchased 
from  a  power  company. 

An  electrical  automatic  pressure  regulator  has  recently  been 
invented  and  is  now  in  successful  use  in  a  number  of  mills  for 
which  the  following  advantages  are  claimed : 

1.  Prevents  peak  load  charges. 

2.  Prevents  overload  on  motors. 


'  194 


MODERN  PULP  AND  PAPER  MAKING 


3.  Eliminates  underloads  so  motors  may  operate  at  prac¬ 
tically  100  per  cent  load  factor. 

4.  Increases  the  production  of  ground  wood. 

5.  Improves  the  quality  and  uniformity  of  the  pulp. 

6.  Reduces  the  amount  of  splinters  or  shives. 

7.  Reduces  the  amount  of  short  fiber  which  is  carried  away 
in  the  white  water. 

8.  Reduces  the  maximum  demand  horse  power  where  power 
is  purchased  and  allows,  when  desirable,  all  motors  to  be  operated 
at  the  exact  value  of  the  generator  capacity  where  a  mill  has  its 
own  power  plant. 

9.  Improves  the  service  rendered  by  the  power  company  by 
maintaining  constant  load  and  better  power  factor  and  voltage 
regulation. 

10.  In  installations  involving  several  grinders,  the  number  of 
grinder  operators  can  be  reduced,  as  supervision  over  the  load 
taken  by  the  grinders  is  not  required. 

11.  Increases  materially  the  electrical  performance  of  the 
motors  and  transformers  by  maintaining  them  at  their  full  load 
efficiency. 

12.  Prevents  shutdowns  on  account  of  overloads  and  conse¬ 
quent  loss  of  production. 

13.  Is  absolutely  “fool  proof”  and  cannot  be  interfered  with 
the  grinder  operators. 

14.  The  regulator  can  be  adjusted  to  control  the  grinder 
load  only  or  the  entire  mill  load. 

15.  Small  amount  of  power  required  to  operate  the  regulator 
— less  than  1-6  h.p. 

16.  Although  the  grinder  operators  have  to  handle  consider¬ 
ably  more  wood,  due  to  the  increased  production,  yet  the  elimina¬ 
tion  of  responsibility  for  peak  loads  and  the  relaxation  from  con¬ 
stant  attention  usually  required  has  .been  welcomed  by  the  men 
in  charge  of  grinders. 

17.  The  regulator  allows  the  power  station  to  figure  on  the 
exact  maximum  demand  of  a  paper  mill,  and  where  several  mills 
are  on  one  line,  the  sum  of  the  individual  maximum  demands 
will  be  the  exact  capacity  necessary  to  be  furnished,  no  extra 
allowance  being  necessary  to  take  care  of  the  overloads. 

18.  The  regulator  is  easily  adjustable  for  load  setting  in  case 
the  demands  of  the  power  station  or  mill  vary. 

The  installation  of  such  a  regulator  does  not  involve  changes 
in  the  system  of  piping,  and  pumps  used  in  mills  can  be  used 
without  any  extensive  alterations,  a  positive  pressure  or  centri¬ 
fugal  type  of  pump  acting  equally  well. 

Regulation  is  obtained  by  automatically  varying  the  water 
pressure  in  the  cylinders  of  the  grinders  so  as  to  obtain  constant 
load  upon  the  motor  driving  them.  Variations  in  load  take  place 
when  the  pressure  is  taken  from  a  cylinder  preparatory  to  charg¬ 
ing  a  pocket  and  again  when  the  pressure  is  reapplied ;  also  dur- 


THE  GROUND  WOOD  MILL 


195 


ing  grinding,  since  less  power  is  required  when  the  circumference 
of  a  log  is  in  contact  with  the  stone  than  when  a  greater  area  of 
contact  is  presented  when  a  log  is  partly  ground  away. 

All  the  above  variations  produce  a  fluctuating  load  and  re¬ 
sultant  loss  in  production,  as  is  obvious  by  an  inspection  of  the 
curves  taken  from  a  graphic  meter  chart. 

It  is  seen  that  without  the  regulator,  as  the  area  of  wood  in 
contact  with  the  stone  varies,  the  power  taken  by  the  motor  varies, 
since  constant  pressure  is  usually  maintained  in  the  cylinders  of 
the  grinder.  In  other  words,  there  is  constant  pressure  in  the 
cylinders,  but  not  constant  unit  pressure  on  the  wood,  since  its 
area  is  varying  continually.  In  order,  therefore,  to  obtain  con¬ 
stant  pressure  per  square  inch  of  wood,  it  is  necessary  to  vary  the 
cylinder  pressure  a  few  pounds  from  normal  to  secure  this,  and 
also  to  maintain  constant  load  on  the  motor. 

Since  pressure  per  square  inch  and  power  variations  can  be 
kept  constant  by  controlling  and  varying  the  normal  water  pres¬ 
sure  by  a  few  pounds,  it  has  also  been  desirable  to  provide  means 
whereby  the  slight  pressure  changes  are  brought  about  gradually 
so  as  to  prevent  the  formation  of  splinters  and  shives,  as  now 
occurs  when  the  wood  is  brought  in  contact  with  the  stone  after 
pressure  is  applied  to  a  pocket.  As  a  result  of  this  and  the  con¬ 
stant  unit  pressure,  not  only  an  increased  production  is  secured, 
but  a  more  uniform  grade  of  pulp  is  obtained.  . 

The  system  of  regulation  most  suitable  for  a  particular  appli¬ 
cation  is  determined  largely  by  the  operating  conditions  which 
obtain  and  the  class  of  product  manufactured.  In  two  mills  hav¬ 
ing  all  conditions  the  same,  that  which  would  be  suitable  for  one 
would  be  wholly  inadequate  for  another.  The  proper  installa¬ 
tion  to  be  made  in  a  given  case,  however,  can  readily  be  deter¬ 
mined  by  a  casual  inspection. 

In  carrying  out  the  installation  of  the  regulator,  a  series  or 
current  transformer  of  suitable  ratio  is  placed  in  circuit  with  the 
motor  driving  the  grinders  and  connected  so  that  fluctuations  of 
load  will  cause  the  moving  element  of  the  primary  regulating  relay 
to  respond  therewith.  This  moving  element  operates  either  up  or 
down,  depending  upon  whether  the  load  is  above  or  below  the  pre¬ 
determined  value,  said  value  being  obtained  by  balancing  the  mov¬ 
able  arm  equally  between  the  contacts  by  a  screw  adjustment 
when  the  indicating  meter  registers  the  desired  load.  As  the  pri¬ 
mary  regulating  relay  element  moves  upward  or  downward  be¬ 
yond  a  certain  adjustable  distance,  a  set  of  contacts  is  closed, 
causing  the  secondary  relay  or  magnet  switch  to  operate,  thereby 
energizing  one  of  the  solenoids  of  an  hydraulic  regulator  valve. 
Instantly,  the  core  of  the  solenoid  is  raised  to  its  extreme  posi¬ 
tion,  opening  both  ports,  which  were  previously  closed,  thereby 
admitting  hydraulic  pressure  to  the  upper  end  of  the  cylinder 
through  the  other  pilot  valve  port,  the  piston  in  the  cylinder 
is  thereby  forced  downward,  opening  to  a  larger  extent  the  bal- 


196  MODERN  PULE  AND  PAPER  MAKING 

anced  regulating  valve.  This  i)ennits  an  increase  in  pressure  in 
the  grinder  cylinders,  thus  increasing  the  load  on  the  motor  driv¬ 
ing  the  grinders. 

As  soon  as  the  electric  load  has  reached  the  point  for  which 
‘the  primary  relay  is  set,  the  primary  circuit  will  be  broken,  caus¬ 
ing  the  secondary  relay  to  break  the  secondary  circuit,  and  the 
core  of  the  solenoid  immediately  drops,  forcing  the  pilot  valve 
pistons  to  the  lower  position,  which  closes  both  ports,  thereby 
preventing  the  admission  or  escape  of  water  from  the  hydraulic 
cylinder,  and  consequently  locking  the  piston  of  the  hydraulic 
cylinder  in  the  exact  position  which  it  occupied  between  one 
valve  closed.  This  is  usually  in  some  mid  position  between  one 
end  of  the  other  of  the  cylinder.  The  piston  in  the  balanced 
regulating  valve  controlling  the  admission  of  water  to  the  grinder 
cylinders  will,  of  course,  occupy  a  corresponding  position  to  that 
of  the  piston  in  the  hydraulic  cylinder,  which  would  be  partly 
open. 

Now,  as  long  as  the  load  remains  constant,  a  state  of  equilib¬ 
rium  will  exist  in  the  system  ;  but  if  the  load  should  increase  above 
the  point  for  which  the  primary  regulating  relay  is  set,  contact 
would  be  made  in  that  direction,  causing  the  other  switch  of  the 
secondary  relay  to  close  its  secondary  circuit,  energizing  the 
other  solenoid,  and  opening  the  other  pilot  valve.  The  opening 
of  this  pilot  valve  opens  both  of  its  ports,  admitting  hydraulic 
pressure  to  the  lower  end  of  the  hydraulic  cylinder  through  one 
of  its  ports  and  exhausting  water  from  the  upper  end  of  the 
cylinder  through  its  other  port. 

The  piston  in  the  cylinder  will  then  be  forced  upward  and  the 
balanced  regulating  valve  piston  correspondingly  raised,  thereby 
shutting  off  some  of  the  pressure  applied  to  the  grinder  pockets 
and  reducing  the  load  on  the  grinder  motor.  As  in  the  first  in¬ 
stance,  when  the  load  reaches  the  value  for  which  the  primary 
regulating  relay  is  set,  the  circuits  will  be  opened,  the  pilot  valve 
returned  to  its  normal  position  at  the  lower  end  of  its  stroke, 
closing  both  ports  and  locking  the  piston  hydraulically  in  some 
mid  position  of  its  stroke  at  whatever  point  it  happened  to  be 
when  the  correct  load  value  is  reached. 

The  primary  regulating  relay  can  be  adjusted  for  any  degree 
of  load  by  simply  raising  or  lowering  a  screw,  so  that  in  localities 
where  the  power  company  changes  the  available  demand  from 
day  to  day,  it  will  be  found  very  easy  to  make  the  desired  adjust¬ 
ment  and  so  prevent  the  occurrence  of  peak  loads. 

In  order  that  there  may  be  stability  in  the  operation  of  this 
regulator,  as  in  the  operation  of  any  governor,  there  must  be  a 
certain  limit  between  the  contacts  of  the  primary  regulating  relay, 
where  the  regulating  valve  will  be  inactive.  One  of  the  most 
vital  points  to  be  met  with  in  the  successful  operation  of  the 
regulator  is  the  length  of  the  time  between  the  change  of  the  load 
on  the  grinder  motor  and  the  change  of  water  pressure  in  the 


THE  GROUND  WOOD  MILL  197 

cylinder  of  the  grinder.  Between  these  limits,  a  number  of  opera¬ 
tions  are  performed,  and  in  accomplishing  the  proper  results,  we 
have  given  considerable  attention  to  the  most  efficient  speed  of 
operation  of  the  regulator ;  that  is,  the  ratio  between  the  speed 
travel  of  the  solenoids  and  the  distance  of  travel  of  the  valve  piston 
controlling  the  admission  water  to  the  grinder  cylinders.  This 
time  ratio  is  adjustable  from  .2  second  and  up,  so  that  an  exact 
point  for  an  installation  can  be  set. 

There  are  several  limiting  points  from  a.  practical  standpoint 
that  must  be  considered,  among  which  is  an  unnecessary  opera¬ 
tion  of  the  regulator,  preventing  close  regulation,  because  the 
time  element  of  the  sequence  of  operations  taking  place  when  the 
pressure  is  to  oe  regulated  has  a  direct  effect  upon  the  hydraulic 
equilibrium  of  the  system.  This  condition  should  not  produce 
hydraulic  oscillations  or  severe  shunting  will  result,  causing  suro-es 
and  inability  to  regulate  with  any  degree  of  accuracy.  ^ 

In  order  to  dampen  any  irregularities  in  the  hydraulic  system, 
use  IS  made  of  a  surge  tank  of  suitable  capacity  and  connected 
with  a  by-pass  check  valve  between  the  main  regulating  valve  and 
the  grinders.  This  surge  tank  acts  in  somewhat  similar  capacity 
to  a  surge  tank  in  a  penstock  line  of  power  plant. 

When  the  balanced  regulating  valve  controlling  the  entrance 
of  water  to  the  grinder  cylinders  is  suddenly  opened  a  certain 
amount  of  increasing  pressure  on  the  side  toward  the  grinders  is 
dissipated  into  the  surge  tank,  cushioning  the  effect  and  prevent- 
ing  an  abrupt  seizure  of  the  wood  upon  the  grinding  stone 
thereby  reducing  the  formation  'of  splinters  and  shives.  When 
the  balanced  regulating  valve  is  suddenly  closed,  to  a  certain 
extent  reducing  the  pressure  at  the  grinders,  a  certain  amount  of 
pressure  is  admitted  from  the  surge  tank,  thereby  eliminating 
any  tendency  for  the  regulator  to  shunt  when  the  by-pass  check 
valve  is  properly  adjusted. 

The  object  of  the  by-pass  check  valve  is  to  prevent  a  large  and 
rapid  delivery  of  pressure  from  the  surge  tank  to  the  grinders, 
but  yet  be  able  to  absorb  considerable  excess  pressure  when  the 
balanced  regulating  valve  is  suddenly  opened.  To  secure  positive 
operation,  compressed  air  is  maintained  in  the  top  portion  of  the 
surge  tank. 

As  a  further  refinement,  the  gate  or  piston  of  the  balanced 
regulating  valve  is  so  designed  that  in  opening  it  the  area  of  port 
opening  increases  as  the  square  of  the  degree  of  raising  of  the 
piston  from  its  seat.  By  this  means  a  heavy  inrush  of  water  is 
prevented  when  the  valve  is  first  opened,  but  an  increasing 
amount  is  allowed  as  the  opening  increases.  When  the  valve 
closes,  the  amount  of  water  is  reduced  speedily  at  first,  but  tapers 
off  to  a  minimum  as  the  piston  approaches  its  seat.  This  gradual 
change  of  water  will  not  be  slow  enough,  however,  to  allow  a 
drop  in  load  on  the  motor,  but  by  this  charactertistic,  abrupt 


198  MODERN  PULP  AND  PAPER  MAKING 

changes  in  pressure  are  prevented  and  smoother  operation  se¬ 
cured. 

In  addition  to  a  regulator  for  motor  operated  grinders,  there 
is  also  a  regulator  for  waterwheel-driven  grinders.  The  appa¬ 
ratus  comprising  this  type  is  similar  to  the  regulator  for  motors, 
except  that  a  centrifugal  governor  belted  to  the  grinder  shaft  is 
substituted  for  the  actuating  solenoid  of  the  primary  regulating 
relay.  This  arrangement  maintains  constant  speed  and  constant 
load,  so  that  the  gate  opening  of  the  waterwheel  may  be  fixed  at 
the  best  position  to  permit  the  most  efficient  operating  speed  of 
the  wheel. 

On  account  of  the  class  of  labor  usually  employed,  the  appa¬ 
ratus  has  been  made  as  near  ‘Tool  proof”  as  possible,  so  that  the 
operation  of  the  regulator  cannot  be  interfered  with  by  the 
grinder  men. 

How  to  Tell  Good  Ground  Wood. 

A  man  accustomed  to  the  manufacturing  of  ground  wood  can 
usually  very  closely  determine  the  quality  of  the  pulp  by  observ¬ 
ing  a  few  simple  rules.  The  flow  of  the  pulp  over  the  grinder 
dams,  the  speed  of  grinders,  pressure  gauge,  the  heat  of  the  pulp 
(judging  from  steam  arising  from  casing  of  grinders  caused  by 
friction),  the  size  of  cylinders,  color  of  pulp,  the  sound  of  the 
grinders,  the  amount  of  slivers  running  into  the  sliver  screen,  etc., 
all  these  points  can  be  observed  in  passing  through  the  grinder 
room  without  a  close  inspection  of  the  pulp.  A  skillful  ground 
wood  pulp  maker  can  casually  walk  through  a  grinder  room  and 
tell  very  closely  the  condition  without  closely  inspecting  the  pulp 
or  asking  questions. 

First — The  pulp  should  be  a  rich  creamy  color;  this  indicates 
that  the  grinders  are  not  allowed  to  run  toe  hot,  sc  that  the  pulp 
is  not  burned. 

Second — The  flow  of  the  pulp  over  the  grinder  dams  should 
reveal  to  the  experienced  eye  the  texture  of  the  pulp.  Coarse 
pulp  will  fill  up  to  the  top  of  the  dam  and  break  over  it  in  chunks 
instead  of  flowing  over  smoothly. 

A  piece  of  blue  glass  set  in  a  small  wooden  frame  is  very 
useful  for  testing  ground  wood.  A  sample  of  the  ground  wood 
is  taken  and  diluted  with  water.  If  the  frame  is  now  held  against 
the  light,  the  fibres  being  white  and  the  light  blue,  the  size,  nature 
and  uniformity  of  the  fibres  can  be  seen  very  clearly.  If  chips, 
shieves,  slivers  or  unseparated  bundles  of  fibres  are  present,  they 
will  be  revealed. 

Another  useful  device  is  the  use  of  a  long,  sharp-pointed  stick 
for  detecting  the  presence  of  holes  and  uneven  spots  on  the 
surface  of  the  stone.  If  such  a  stick  is  held  against  the  surface 
of  the  stone  as  it  revolves,  being  gradually  moved  across  the 
surface,  any  irregularities  in  surface  will  reveal  themselves  by 
making  the  stick  vibrate.  The  sense  of  touch  will  soon  learn 


THE  GROUND  WOOD  MILL  199 

to  detect  even  very  slight  defects  in  the  surface  of  the  stone. 
This  device  obviates  the  necessity  of  shutting  down  the  grinders 
to  find  out  if  the  stones  need  burring,  etc. 

TYPICAL  SPECIFICATIONS  FOR  GRINDER. 

To  be  latest  design  and  finish,  having .  pockets  and 

taking  a  stone  54"  in  diameter,  27"  face  for  25"  wood. 

Base  Plates:  The  Base  Plates  are  of  cast  iron  6’  long,  in  the  form 
of  an  angle  plate,  the  vertical  part  forming  part  of  the  grinder  side  up 
to  the  shaft  center.  Top  of  upright  is  planed  to  receive  the  sides.  At 
each  end  of  the  base  plate  will  be  a  socket  suitable  for  the  boss  on  the 
side  frames,  the  two  together  forming  the  hinge  of  the  side  frames 
when  they  are  lifted.  The  base  plate  is  thick  on  the  horizontal 

part  and  1%  thick  on  the  upright  and  is  heavily  ribbed  to  insure  rigidity. 

A  pad  is  case  on  the  base  together  with  lugs.  The  pad  is  machined 
to  receive  main  journals  and  lugs  are  fitted  for  the  adjusting  screws. 

Four  holes  are  bored  in  the  plates  for  the  anchor  bolts. 

Sides:  The  Grinder  sides  to  be  made  of  cast  Iron,  heavy  in’design 
with  strengthening  ribs  under  each  pocket  and  to  be  machine  finished 
where  all  connections  are  made.  These  frames  to  be  made  of  our  latest 
pattern  which  is  thoroughly  well  suited  to  its  duty.  The  side  of  each 
frame  will  be  slotted  for  the  adjusting  bolts  which  secure  the  pockets 
m  position ;  the  slots  to  be  reinforced  with  strengthening  ribs.  On  the 
inside  of  the  grinder  case  there  are  to  be  three  2"  ribs  for  each  pocket- 
the  center  ribs  to  be  planed  to  extend  14"  higher  than  the  ribs  on  either 
side  of  same.  On  the  end  of  each  pocket  there  is  to  be  a  groove  planed 
to  correspond  with  the  extended  ribs  in  these  grinder  sides.  The  bottom 
of  the  flange  of  the  grinder  side  where  it  connects  with  the  base  plate 
is^  machine  finished  and  to  have  slotted  holes  for  the  six  through  bolts, 
i"  diameter.  To  the  grinder  sides  around  the  shaft  is  fitted  a  case  to 
be  packed  with  rubber  packing  to  prevent  the  stock  running  out.  These 
sides  when  placed  in  position  stand  37"  apart. 

Pockets:  The  Pockets  are  P/L'  thick,  made  of  cast  iron  and  each  in 
one  casting.  Length  of  pocket  inside  25^".  The  pocket  doors  will  take 
wood  14  in  diameter.  Three  strips  are  cast  on  both  sides  of  inside  of 
pockets  to  assist  in  the  alignment  of  the  piston  rod,  and  reduce  friction  of 
the  wood.  The  ribs  extend  from  top  to  bottom.  The  working  side  of 
the  pocket  at  the  bottom,  which  extends  across  the  face  of  the  stone,  is 
fingered  also  the  ends.  The  pocket  can  be  so  adjusted  that  this  face  will 
just  clear  the  stone  largely  preventing  slivers.  The  opposite  side  of 
the  pocket  is  cut  out  at  the  bottom,  to  give  ample  room  for  possible 
slivers.  Provision  is  made  to  prevent  accumulation  of  slivers  between 
pockets.  The  ears  on  each  side  for  supporting  the  pocket  in  the  proper 
position  are  3^"  deep,  through  which  the  adjusting  bolts  pass.  A  strong 
ribbed  foot  extends  at  each  end  of  the  pocket  for  connecting  same  to 
the  sides.  Can  adjust  the  pockets  from  the  54"  diameter  stone  to  58" 
diameter  stone.  The  top  and  ends  are  ma-chine  finished.  The  top  of 
pockets  are  completely  covered  by  the  bottom  head  of  the  hydraulic 
cylinders,  preventing  any  pulp  flying  out.  The  pockets  at  each  end  or 
side  where  they  come  against  the  frame  are  machined,  provided  with  a 
groove^  in  which  the  raised  rib  on  frame  of  grinders  forms  a  guide, 
which  is  machine  finished  to  size  2"  wide  thick,  so  that  whether  the 
pockets  are  up  to  a  54"  stone,  or  down  to  a  38"  stone,  the  pockets  always 
maintain  the  same  position  in  these  guides  and  cannot  move  out  by  the 
center  line  of  machine  in  either  direction.  The  adjustment  is  given  to 
the  pockets  by  tAvo  large  bolts,  2"  diameter  with  double  jam  nuts  on  each  . 
side  of  pocket  wings.  To  further  insure  the  pockets  from  shifting  their 
position  and  partly  to  relieve  the  adjusting  screws  of  the  tension  imposed 
on  them,  bolts  passing  through  the  side  frame  and  sides  of  pockets  are 


200 


MODERN  PULP  AND  PAPER  MAKING 


provided.  The  position  of  the  pockets  on  the  grinders  are  at  such  an 
angle  that  the  pulp  after  being  ground  will  not  hang  up  in  the  pockets. 
On  the  bottom  of  three  sides  of  the  pockets  are  2"  fingers  for  discharge 
of  the  pulp,  which  will  prevent  larger  slivers  from  working  out. 

Pocket  Doors:  The  Pocket  Doors  are  made  of  soft  steel  YA  thick. 
Size  of  door  14x14^4".  These  doors  slide  in  a  groove  and  are  held  in 
position  by  a  guide  which  is  connected  to  the  pocket.  Fittings  for  guide 
pieces  are  brass.  The  handles  for  doors  are  cast  iron. 

Pillow  Blocks:  The  Pillow  Blocks  or  main  bearing  are  to  be  heavy 
cast  iron  boxes  having  a  bearing  for  the  shaft,  i8j4"  long.  The  boxes 

arp  to  he  ^  babbitted 

\  wood  lined 

Our  babbitted  box  is  of  a  water-cooled  oil  ring  type,  so  designed  that 
a  water-circulation  is  kept  up  in  each  box  thus  keeping  it  cool.  Our 
best  copper  hardened  babbit  is  to  be  used,  the  box  then  bored  and  fitted 
to  the  shaft. 

Our  wood  lined  boxes  are  lined  with  blocks  of  maple  after  being 
boiled  in  tallow.  The  box  is  then  bored  out  to  fit  shaft. 

These  boxes  are  adjusted  by  means  of  the  two  wedges  on  which  they 
rest.  The  wedges  in  turn  are  adjusted  by  two  screws  with  lock  nuts 
fitted  to  the  two  lugs  on  the  base  plate. 

These  wedges  are  planed  on  the  face  thereby  rendering  adjustment 


easy. 

Yokes  or  Bridgetrees:  The  Yokes  are  of  cast  iron  44"  long,  5"  wide, 
one  on  each  side  of  the  pocket.  They  are  heavy  and  heavy  ribbed  from 
the  ends  to  the  center.  A  pocket  is  bored  in  each  to  receive  the  adjusting 
screw  nut.  The  top  is  flanged  to  receive  the  two  adjusting  screws  which 
support  the  grinder  pockets.  The  yokes  are  machine  finished  where  they 
connect  to  the  grinder  sides. 

Bottom  Cylinder  Heads  of  Saddles:  The  Bottom  Cylinder  Heads  are 
accurately  fitted  to  cylinder  and  cover  the  entire  pocket.  Bored  for  brass 
gland  and  piston  rod.  A  brass  ring  is  fitted  in  each  head  under  packing 
gland.  This  brass  ring  will  take  all  the  wear  of  the  piston  rod.  It  can 
be  removed  and  a  new  one  put  in  its  place,  thereby  saving  the  lower 
cylinder  head.  The  brass  gland  is  split  and  made  heavy  and  deep,  in¬ 
suring  a  good  packing.  The  head  has  a  door,  front  and  back,  which  can 
be  quickly  removed  when  gland  requires  readjusting  or  repacking.  This 
head  is  heavily  ribbed ;  is  machine  finished  where  it  connects  to  top  of 
grinder  pocket,  and  is  held  in  position  by  eight  stud-bolts,  hex  nuts. 
The  brass  gland  is  held  in  position  by  three  YP  brass  stud-bolts  and 
hex  brass  nuts. 

Hydraulic  Cylinders:  The  Hydraulic  Cylinders  are  22"  long,  Y"  thick 
with  flanges  on  each  end  YA  thick.  The  face  of  flanges  are  machine 
finished ;  also  outside  diameter  of  lower  flange,  which  is  made  to  enter 
lower  cylinder  head,  insuring  perfect  alignment.  The  cylinder  is  .bored 

to  receive  a  hard-drawn  seamless  brass  tubing . inches  inside 

diameter,  YA  thick.  This  tubing  is  forced  into  place  under  pressure  and 
rolled.  The  side  of  the  cylinder  shell  is  fitted  to  receive  the  hydraulic 
valve.  There  is  no  piping  between  valve  and  cylinder.  Cylinder  and 
valves  are  all  tested  before  leaving  the  factory. 

Top  Cylinder  Head:  The  Top  Cylinder  Head  is  nicely  fitted  to  the 
cylinder,  and  made  to  enter  inside  diameter  of  cylinder,  making  perfect 
alignment.  Fitted  with  heavy  brass  gland  using  YP  square  packing.  This 
gland  is  also  made  deep,  insuring  ample  packing  for  the  work.  '  The 
glands  are  held  in  position  by  three  YA  brass  stud-bolts  with  hex  brass 
nuts.  All  cylinder  heads  connect  to  cylinder  with  seven  YA  bolts  with 
hex  nuts. 

Hydraulic  Piston  Rods:  The  Hydraulic  Piston  Rods  are  made  of  soft 
steel  5'  8"  long,  2-15/16"  diameter  at  the  lower  end,  and  2Y"  at  the  upper 
end,  which  passes  through  the  top  cylinder  head.  The  Piston  Head  and 


THE  GROUND  WOOD  MILL 


201 


follower  are  held  in  position  on  the  piston  rod  by  two  brass  hex  nuts, 
one  being  a  jam  nut. 

Piston  Head  and  Follower:  The  Piston  Head  and  Follower  are  \/i6" 
less  in  diameter  than  the  bore  of  the  cylinders.  The  heads  slip  against 
a  shoulder  bearing  on  piston  rod.  The  follower  is  YL'  thick  and 
thick  through  the  hub  and  held  against  the  packing  and  head  by  two 
brass  nuts  on  the  piston  rod.  These  heads  are  packed  with  six  rings  of 
flax  packing  square.  The  piston  is  fitted  with  a  cast  iron  spring 
ring,  2^"  wide. 

Pocket  Follower:  The  Pocket  Follower  is  made  of  good  strong  gray 
iron  from  a  straight  pattern  and  having  the  ribbed  surface  where  it 
comes  in  contact  with  the  wood.  It  is  24"  long,  in  width  just  clearing 
the  sides  of  the  pocket.  Diameter  of  the  hub  sW'.  Heavy  ribs  extend 
from  the  hub  to  corners.  This  follower  is  pressed  and  bolted  on  piston 
rod. 

Shafts:  The  Shafts  are  made  from  steel  forgings . inches 

in  diameter  in  the  bearings  and . inches  in  the  stone.  Threads 

for  flanges  are  cut  so  both  flanges  slip  off  same  end  of  the  shaft.  Two 
half  “V”  threads  to  the  inch  to  receive  the  flanges,  cut  right  and  left  hand. 
End  of  shaft  fitted  to  large  wrench  for  removing  stone. 

Grinder  Flanges:  The  Grinder  Flanges  are  made  from  steel  castings 
38"  diameter,  through  hub.  Machine  finished  where  face  of  flanges 
come  in  contact  with  stone.  Four  H/i"  holes  through  flanges  in  which 
are  fitted  two  steel  pins  for  removing  flanges  from  shaft.  Threads  are 
cut  right  and  left  hand  to  fit  grinder  shaft. 

Couplings:  (Flange  )  Couplings  made  of  good  strong  gray  iron. 

(Compression)  Outside  diameter . hub  diameter 

. length  of  coupling.  Couplings  lock  on  face. 

Tools:  One  large  wrench  for  removing  flanges  from  shaft,  also  set 
of  steel  wrenches  for  nut  on  the  grinders.  One  stone  trueing  tool  with 
disc  holder  and  six  discs ;  one  burr  holder  and  six  cast  iron  burrs. 

Fittings  and  Piping:  Each  grinder  fitted  with  three  improved  4- way 
valves. 

Packing:  All  cylinder  heads  are  put  on  with  sheet  packing  1/16"  thick. 

Painting:  All  grinders  to  be  painted  with  good  durable  paint. 


XI.  Bleaching 

Wood  pulp,  regardless  of  the  process  by  which  it  is  made, 
requires  to  be  bleached  if  it  is  to  be  used  m  any  of  the  finer 
varieties  of  light  colored  paper. 

Rag  pulp,  straw  pulp  and  pulp  made  from  esparto,  jute,  etc., 
and  most  of  the  other  miscellaneous  materials  from,  which  paper 
of  any  kind  is  made,  require  bleaching  in  order  to  enhance  the 
value  of  the  product. 

The  bleaching  of  rag  stock  is  a  comparatively  simple  matter 
owing  to  the  comparative  freedom  of  such  stock  from  colored  im¬ 
purities  which  have  to  be  eliminated  by  the  bleaching  agent.  It 
should  be  borne  in  mind  that  most  rag  stock  of  the  better  grade 
is  made  from  material  which  has  already  been  submitted  to 
bleaching  in  the  processes  of  textile  manufacturing,  and  any  color¬ 
ing  matter  which  may  be  present  is  in  the  form  of  dyes  which 
have  been  added  by  the  textile  manufacturer  or  finisher,  and 
which  are  relatively  easy  to  remove  when  compared  with  the 
coloring  materials  embodied  in  wood  pulp  which  are  an  integral 
part  of  the  fibre  itself. 

Wood  pulp,  no  matter  how  carefully  made,  and  whether  pro¬ 
duced  by  the  sulphite  or  soda  process,  always  has  associated  with 
the  cellulose  a  portion  of  the  lignin  or  incrusting  matter  ordinarily 
present  in  the  raw  fibre  and  this  lignin  carries  with  it  certain  col¬ 
ored  bodies  of  highly  complex  chemical  composition.  These  col¬ 
ored  impurities  cannot  be  removed  by  any  amount  of  washing  or 
mechanical  treatment.  They  are  united  in  a  chemical  manner 
with  the  fibre  or  cellulose  and  a  chemical  process  is  necessary  for 
their  removal. 

In  addition  to  the  colored  materials  that  are  ordinarily  present 
in  the  fibre,  other  dark  colored  substances  are  produced  during  the 
process  of  digesting  the  pulp,  by  the  chemical  action  of  the  acid  or 
alkaline  liquids  on  the  various  complex  substances  contained  in 
natural  wood. 

Wood  pulps  and  pulps  made  from  esparto,  straw,  jute,  etc., 
require,  as  pointed  out  above,  a  much  more  drastic  bleaching  than 
rag  pulp,  resulting  in  a  much  larger  consumption  of  the  chemical 
used  for  bleaching  purposes  and  a  much  greater  proportional  loss 
in  weight  through  the  bleaching^process. 

The  object  of  all  successful  bleaching  practice  in  the  paper  in¬ 
dustry  is  to  thoroughly  bleach  the  pulp  so  as  to  turn  out  a  product 
of  maximum  whiteness  and  purity,  which  will  remain  white  in¬ 
definitely,  and,  at  the  same  time,  not  to  impair  the  strength  and 

202 


BLEACHING  203 

natural  properties  of  the  fibre,  not  to  cause  too  much  shrinkage 
in  weight  and  volume,  and  not  to  have  an  excessive  consumption 
of  the  bleaching  agent.  ^ 

Naturally,  as  in  any  other  process,  it  is  also  desirable  to  reduce 
the  labor  employed  in  the  process  to  a  minimum  and  consequently 
whereas  bleaching  was  formerly  carried  out  in  simple  tanks  pro¬ 
vided  with  more  or  less  crude  agitators,  at  the  present  time  numer¬ 
ous  highly  efficient  special  forms  of  bleaching  equipment  are  on 
the  market,  all  of  which  are  designed  with  the  idea  of  making  the 
process  as  largely  automatic  as  possible. 

Rag  pulp  is  frequently  bleached  in  a  Hollander  or  washer  in 
which  the  boiled  rags  are  given  the  preliminary  treatment  which 
converts  the  stock  into  what  is  known  as  “half-stuff  ”  As  a  rule 
in  bitching  this  kind  of  stock,  no  special  bleaching  equipment  is 
provided,  the  bleaching  agent  being  added  to  the  Hollander  to¬ 
wards  the  final  stages  of  the  operation  and  washing  being  con¬ 
tinued  sufficiently  long  after  the  bleaching  effect  has  been  accom¬ 
plished  to  wash  out  the  impurities  and  the  surplus  bleach. 

Bleaching  Agents. 

Bleaching  is  essentially  an  oxidizing  reaction.  This  is  shown 
by  the  fact  that  many  materials  will  become  bleached  when  simply 
left  exposed  to  the  wind  and  weather.  All  of  the  various  chem¬ 
icals  used  for  bleaching  purposes  are  used  with  the  idea  of  oxidiz- 
ing  the  colored  materials  and,  of  all  these  bleaching  agents,  the 
commonest  are  certain  of  the  compounds  of  chlorine.  Chlorine, 
when  brought  in  contact  with  water,  releases  the  oxygen  of  the 
water  and  it  is  this  freshly  released  oxygen  that  exerts  the  de¬ 
colorizing  action  on  the  fibre. 

The  commonest  bleaching  agent  is  bleaching  powder,  a  white 
substance  having  a  distinct  odor  of  chlorine.  It  readily  absorbs 
moisture  from  the  air  and  for  this  reason  must  be  kept  in  covered 
drums  or  other  vessels  which  will  exclude  air.  The  chemical 
composition  of  bleaching  powder  is  not  very  definite,  but  the 
formula  CaOCU  is  generally  accepted.  The  material  is  bought 
and  sold  on  the  basis  of  the  amount  of  “available  chlorine”  pres¬ 
ent  in  the  bleaching  powder.  Good  commercial  bleaching  powder 
or  chloride  of  lime,  as  it  is  frequently  called,  should  contain  from 
35  1^0  37  per  cent  available  chlorine. 

Bleaching  powder  is  usually  shipped  in  steel  drums  or  wooden 
barrels.  The  steel  drums  weigh  from  100  to  800  pounds  includ¬ 
ing  the  weight  of  the  drum,  and  the  wooden  barrels  usually  weigh 
from  350  to  415  pounds  including  the  weight  of  the  barrels.  An 
8oo-pound  steel  drum  such  as  is  ordinarily  used  for  the  shipment 
of  bleaching  powder  measures  30x39^  inches.  Where  it  is  nec¬ 
essary  to  use  this  material  in  small  quantities  it  is  usually  pur¬ 
chased  in  5-  or  lo-pound  cans  and  this  is  frequently  a  convenient 
way  of  buying  and  storing  the  material  as  the  slightly  increased 


204  MODERN  PULP  AND  PAPER  MAKING 

cost  on  account  of  the  containers  will  be  more  than  offset  by  the 
prevention  of  deterioration  in  the  material. 

In  Europe  bleaching  powder  is  frequently  sold  on  a  degree 
basis,  the  degrees  representing  the  volume  of  chlorine  which  will 
be  liberated  from  one  kilogram  of  the  bleaching  powder  at  stand¬ 
ard  temperature  and  pressure.  The  following  is  a  table  of  the 
relation  of  French  degrees  to  “available  chlorine”  as  given  in 
Griffin  and  Little.^ 


Relation  of  French  Degrees  to  Percentage  of  Available  Chlorine 


French  Degrees 


Percentage 

Available 

Chlorine 


Percentage 
French  Degrees  Available 
Chlorine 


65 

20.65 

70 

22.24 

75 

23  83 

80 

25-42 

85 

27.01 

90 

28.60 

95 

30.21 

100 

31.80 

105 

33-36 

1 10 

34-95 

115 

36.54 

120 

38.13 

125 

39-72 

130 

41-34 

Bleaching  powder  requires  great  care  in  shipment  and  storage. 
If  the  powder  is  allowed  to  become  wet,  or  even  damp,  it  will 
rapidly  deteriorate  and  lose  a  large  percentage  of  its  available 
chlorine.  In  case  the  powder  should  become  actually  wet,  as 
might  happen  in  a  leaky  ship  or  a  bad  car  exposed  to  the  weather, 
the  decomposition  may  be  so  rapid  as  to  cause  explosions. 

Griffin  and  Little  mention  a  series  of  experiments  carried  out 
by  Pattinson  regarding  the  rate  at  which  bleaching  powder  deteri¬ 
orated  in  storage.  Pattinson  took  three  6oo-pound  barrels  of 
bleaching  powder;  12  bottles  of  the  same  powder  were  filled  at 
the  same  time.  The  barrels  were  sealed  and  both  the  barrels  and 
bottles  were  stored  in  a  cellar.  A  maximum  and  minimum  ther¬ 
mometer  was  placed  near  them,  and  a  careful  record  of  the  tem¬ 
perature  made  for  each  working  day  of  the  year.  The  record 
shows  the  temperature  to  have  been  uniform  and  comparatively 
low  during  the  entire  year,  the  highest  being  62°  F.,  and  the  lowest 
38°  F.  One  bottle  from  each  of  the  three  sets  of  twelve  was 
opened  and  tested  each  month,  and  a  sample  was  also  withdrawn 
and  tested  from  each  of  the  three  casks.  The  results  of  the  ex¬ 
periment  shows  a  gradual  and  regular  loss  of  available  chlorine 
during  the  time  over  which  the  tests  were  made.  The  average 
loss  in  the  barrels  was  about  one-third  of  one  per  cent  greater 
than  in  the  bottles  and  the  barrels  were  not  necessarily  air-tight. 
A  complete  analysis  of  each  of  the  barrel  samples  was  made  at 
the  beginning  and  also  at  the  end  of  the  experiment.  These 
analyses  are  given  in  the  table  below : 


^  The  Chemistry  of  I’ajier  Making. 


205 


BLEACHING 

Composition  of  Bleaching  Powder 


January  29, 

1885 

January  5, 

1886 

A 

B 

C 

A 

B 

C 

Available  chlorine . 

37.00 

3«-30 

36.00 

38.80 

35  10 

32.90 

Chlorine  as  chloride . . . 

0-35 

0.59 

0.32 

2.44 

2.42 

I  97 

Chlorine  as  chlorate . . . 

0,25 

0.08 

0.26 

0.00 

0.00 

0.00 

Lime . 

44  49 

43-34 

44 . 66 

43-57 

.42.64 

43-65 

Magnesia . 

0.40 

0.34 

0.43 

0.31 

0.36 

0.38 

Silicious  matter . 

0.40 

0.30 

0.50 

0.50 

0.40 

0.50 

Carbonic  acid . 

0. 18 

0.30 

0.48 

0.80 

1 .48 

1-34 

Alumina,  perioxide  iron 
oxide  manganese .... 

0.48 

0  45 

0.35 

0.40 

0.40 

0.37 

Water  and  loss . 

16.45 

16.33 

17.00 

18.18 

17.20 

18.89 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

Total  chlorine . 

37.60 

38.97 

36.58 

36.24 

37-52 

34-87 

The  small  quantity  of  chlorine  found  as  chlorate  at  the  begin¬ 
ning  of  the  experiments  ceased  to  exist  in  this  combination  at  the 
end,  and  from  tests  made  it  was  found  that  all  the  chlorate  had 
disappeared  about  four  months  after  the  barrels  were  filled.  The 
amount  of  chlorine  existing  as  chloride  had  slightly  increased.  It 
is  not  often  that  bleaching  powder  can  be  stored  where  so  low  a 
temperature  as  6o°  F.  can  be  maintained  for  any  length  of  time, 
especially  in  the  summer  months  when,  as  previous  experiments 
have  indicated,  the  greatest  loss  of  available  chlorine  takes  place. 

Bleaching  powder  should  be  stored  in  as  dry  a  place  as  possi¬ 
ble,  or,  better,  in  one  that  is  both  dry  and  cool;  and  if  any  of  the 
containers  are  damaged,  they  should  be  the  first  ones  selected  for 
use. 

According  to  Griffin  and  Little,  the  rate  at  which  the  bleaching 
powder  deteriorates  is  influenced  by  the  kind  of  container  in 
which  it  is  packed.  •  Soft  woods  are  considerably  affected  by  the 
action  of  the  powder,  and  shrink  badly  when  exposed  to  the  sun. 
If  such  containers  are  subsequently  exposed  to  rain,  water  readily 
finds  its  way  into  the  barrels.  Ash  and  other  hardwoods  can  be 
used  for  such  barrels,  but  the  best  barrels  are  built  of  oak  staves 
one  inch  in  thickness. 

The  leading  companies  manufacturing  bleaching  powder  have 
given  very  careful  atteniton  to  the  containers  in  which  this  ma¬ 
terial  is  shipped  and  if  it  is  purchased  from  a  reliable  concern, 
little  trouble  will  probably  be  experienced  with  deterioration  in 
shipment  or  storage. 

Preparation  of  the  Bleaching  Liquor. 

The  usual  method  of  preparing  bleaching  liquor  is  to  place  a 
suitable  quantity  of  bleaching  powder  in  an  iron  tank  provided 
with  an  agitator.  These  tanks  are  usually  painted  with  red  lead 
ground  in  oil.  The  mixture  is  agitated  thoroughly  and  thfe  agita¬ 
tor  then  stopped,  allowing  the  mud  to  settle.  The  liquid  is  then 
drawn  into  a  second  settling  tank  in  which  the  finer  sediment 


2o6  modern  pulp  and  PAPER  MAKING 

settles  out.  The  slime  remaining  in  the  agitator  is  again  treated 
with  a  fresh  quantity  of  water  and  the  weak  solution  thus  ob¬ 
tained  is  drawn  off  into  a  storage  tank  from  which  it  is  taken 
for  the  treatment  of  a  new  lot  of  bleaching  powder.  In  this 
way  the  utmost  economy  in  the  use  of  material  is  obtained.  The 
slime  should  be  sampled  and  sent  to  the  laboratory  from  time  to 
time  so  as  to  determine  if  the  washing  is  being  carried  out  in  a 
sufficiently  thorough  manner  to  extract  the  maximum  percentage 
of  available  chlorine. 

The  bleaching  liquor  should  be  very  thoroughly  settled  and 
decanted  before  being  used  in  the  Hollander  or  special  bleaching 
equipment.  Not  only  is  the  muddy  bleaching  liquor  less  efficient 
than  a  pure  solution,  but  it  also  contains  dirt  which  will  cause 
black  specks  in  the  paper. 

A  hydrometer  is  usually  used  for  testing  the  strength  of  the 
bleaching  liquor.  This  is  a  very  inaccurate  method  of  testing 
this  liquor  because  there  is  not  necessarily  any  definite  relation 
between  the  density  of  the  solution  and  the  amount  of  available 
chlorine  present.  If  the  mill  has  adequate  laboratory  facilities  it 
would  be  much  better  to  take  samples  at  regular  intervals  and 
have  these  sent  to  the  laboratory  for  a  determination  of  the  avail¬ 
able  chlorine  present.  However,  the  hydrometer  test  is  better 
than  nothing,  and  in  many  mills  is  the  only  practical  method  that 
can  be  used.  According  to  Griffin  and  Little  it  may  be  accepted 
as  a  rough  rule  that  i°  Be.  on  the  hydrometer  averages  about 
0.47  per  cent  available  chlorine  in  the  solution. 

Chlorine  Bleach. 

Recently,  since  highly  purified  chlorine  gas  has  become  an 
article  of  commerce,  being  sold  in  liquefied  form  in  steel  cylin¬ 
ders,  considerable  work  has  been  done  on  the  bleaching  of  pulp 
(and  also  textiles  and  other  materials)  with  liquid  chlorine  in¬ 
stead  of  bleaching  powder. 

Very  pure  liquid  chlorine  is  now  being  placed  on  the  market 
by  several  firms  at  a  reasonable  price.  It  is  shipped  in  steel 
cylinders  containing  from  100  to  150  pounds  and  can  also  be 
shipped  in  tank  cars  containing  30,000  pounds.  The  cylinders 
measure  53  in.  by  83/2  to  103/2  in.  The  following  is  an  analysis 
of  the  chlorine  sold  by  one  of  the  leading  manufacturers  of  this 
product : 


Chlorine .  99.80  per  cent  to  99 . 99  per  cent 

Carbon  Dioxide .  o.oi  per  cent  to  0.20  per  cent 

Air  and  Oxygen .  0.00  per  cent  to  o.  10  per  cent 


The  lise  of  liquid  chlorine  obviates  all  the  labor,  trouble  and 
uncertainty  of  making  up  bleaching  liquors  from  bleaching  pow¬ 
der  and  water.  Highly  efficient  special  proportioning  valves  have 
been  devised  that  will  automatically  admit  enough  chlorine  to 
the  water  to  make  the  solution  up  to  any  required  percentage 


BLEACHING 


207 


of  available  chlorine.  The  convenience  and  simplicity  of  this 
method  is  rapidly  becoming  more  and  more  appreciated  and  un¬ 
doubtedly  will  be  used  to  an  increasing  extent  in  the  future. 

The  Bleaching  Process. 

We  are  indebted  to  an  article  by  James  Beveridge  in  “Paper” 
for  Oct.  30,  1918,  for  much  of  the  following  information  con¬ 
cerning  the  bleaching  process.  The  bleaching  properties  of  a 
pulp  depend  upon  the  process  by  which  it  is  prepared.  As  a 
general  rule  vegetable  fibre  when  prepared  by  the  sulphite  process 
bleaches  more  readily  than  that  prepared  by  the  soda  or  sulphate 
process. 

Also  sulphite  pulp  made  with  an  acid  high  in  magnesia  usually 
bleaches  more  readily  than  a  pulp  made  with  an  acid  prepared 
from  straight  limestone. 

The  quality  of  the  water  used  for  cleaning  the  pulp  also  has 
an  influence  on  the  bleaching  process,  especially  if  the  water  con¬ 
tains  lime  in  any  form.  In  the  sulphite  process  the  lime  salts 
precipitate  insoluble  resin  soaps  on  the  surface  of  the  fibre  which 
absorb  chlorine  in  proportion  to  their  presence,  and  in  order  to 
avoid  such  precipitation  the  water  is  sometimes  heated  to  boiling 
or  chemically  treated  for  the  removal  of  lime  before  it  is  used. 
A  similar  precipitation  of  lime  salts  takes  place  when  water  con¬ 
taining  lime  is  used  for  washing  soda  or  sulphate  pulp,  the  lime 
being  precipitated  either  as  carbonate  or  sulphate  by  the  alkali 
present.  Both  of  these  substances  cling  to  the  fibre  and  carry 
down  with  them  organic  coloring  matter  which  renders  the  proc¬ 
ess  of  bleaching  even  more  difficult  and  costly  than  is  the  case 
with  sulphite  pulps. 

The  loss  of  weight  in  bleaching  pulp,  together  with  the  cost 
depends  on  many  factors,  the  most  important  of  which  may  be 
enumerated  as  follows : 

1.  The  raw  material  from  which  the  pulp  is  prepared. 

2.  The  process  employed  for  manufacturing  the  cellulose  or 
fibre,  whether  this  be  alkaline  or  acid,  i.  e.,  soda  or  sulphite 
process. 

3.  The  purity  of  the  pulp  obtained,  controlled  largely  by  the 
conditions  under  which  the  fibre  is  prepared,  such  as  the  amount, 
character  and  composition  of  the  chemicals  used  in  cooking;  the 
temperature  employed ;  the  time  given  to  complete  the  process ; 
the  purity  of  the  water  used  for  washing. 

4.  The  dilution  of  the  pulp  with  water,  or  density  of  the 
stock,  during  the  bleaching  operation,  which  insures  a  more  inti¬ 
mate  and  closer  contact  of  the  bleaching  agent  with  the  fibre. 

5.  The  temperature  at  which  the  bleaching  is  carried  out  and 
the  consequent  acceleration  of  the  chemical  action  between  the 
chlorine  and  the  coloring  matter. 

6.  The  time  allowed  for  bleaching,  controlled  by  the  tem¬ 
perature  and  density  of  the  stock  under  treatment. 


2o8  modern  pulp  and  PAPER  MAKING 

With  regard  to  these  factors,  it  has  been  found  in  manufac¬ 
turing  practice  that  the  greater  the  yield  of  fibre  from  unit 
weight  of  raw  material,  no  matter  by  what  process  the  pulp  has 
been  made,  the  greater  is  the  loss  of  weight  of  pulp  bleached  and 
the  amount  of  bleaching  agent  required.  It  has  also  been  found 
that  the  dilution  of  the  fibre  with  water  or  density  of  the  stock, 
and  the  temperature  employed  for  bleaching,  are  most  important 
since  the  first  manifestly  results  in  great  economy  of  steam  and 
the  second  in  economy  of  bleach. 

Bleaching  Equipment. 

In  the  following  paragraphs  describing  bleaching  equipment 
we  have  drawn  liberally  on  the  information  in  Mr.  Beveridge’s 
excellent  article  in  “Paper”  for  Oct.  30,  1918. 

In  the  older  methods  of  bleaching,  the  Hollander  with  a  paddle 
wheel  to  throw  the  pulp  over  the  backfall  instead  of  a  roll,  and 
sometimes  called  a  “pocher”  was  used,  the  fibre  being  allowed  to 
circulate  either  cold  or  hot  until  the  required  degree  of  whiteness 
was  attained.  The  stock  at  first  was  washed  in  the  Hollander 
after  bleaching  with  drum  washers,  the  washings  containing  the 
excess  bleach  being  thrown  away.  Or,  instead  of  washing,  a 
quantity  of  antichlor  or  sodium  hyposulphite  was  added  to  de¬ 
stroy  the  excess  of  hypochlorite  present.  This  was  obviously  a 
very  wasteful  method  and  a  distinct  improvement  was  the  intro¬ 
duction  of  a  special  draining  tank,  usually  built  of  concrete  and 
provided  with  a  perforated  false  bottom  of  earthenware  tiles,  into 
which  the  pulp  was  emptied  and  drained,  the  liquor  being  pumped 
back  again  to  the  “pocher”  to  be  mixed  with  a  quantity  of  fresh 
unbleached  pulp,  so  as  to  exhaust  any  available  chlorine  it  con¬ 
tained.  These  draining  tanks  are  in  use  today  in  many  paper  mills. 

A  still  further  advance  was  made  when  a  series  of  open  con¬ 
crete  tanks  was  put  down  to  bleach  and  store  large  quantities  of 
pulp,  the  main  principle  being  to  thoroughly  mix  the  bleach  liquor 
and  pulp  together  in  a  suitable  Hollander  or  “pocher,”  and  after 
steaming  to  the  required  temperature  running  the  whole  charge 
into  a  tank,  there  to  remain  till  the  fibre  came  up  to  the  requisite 
degree  of  whitness,  a  slight  excess  of  bleach  liquor  being  added 
for  this  purpose.  The  liquor  was  then  drained  off  into  a  well 
and  from  there  pumped  back  to  the  “pocher”  to  meet  fresh  un¬ 
bleached  pulp,  thus  becoming  exhausted  of  its  available  chlorine. 
The  density  of  the  stock  was  in  all  cases,  attained  with  the  drum 
washer. 

An  arrangement  of  the  kind  described  above  is  shown  in  the 
illustration.  The  fibre  direct  from  the  screens  flows  into  the 
“pocher”  a,  and  after  the  desired  density  has  been  obtained  with 
the  drum  washer,  the  bleach  liquor  is  added  and  the  whole  cir¬ 
culated  for  a  couple  of  hours  or  so,  steam  being  injected  mean¬ 
while  till  the  temperature  reaches  100°  to  110°  to  120°  F.  The 
charge  is  then  run  off  through  the  chute  b,  into  any  one  of  the 


BLEACHING 


209 


series  of  tanks  c,  where  it  remains  at  rest  for  twelve  or  sixteen 
hours.  By  this  time  the  pulp  will  have  reached  a  good  color. 
The  liquor  is  then  drained  off  through  the  plug  hole  d,  into  the 
pipe  e,  which  conveys  it  to  the  well  f,  from  whence  it  is  pumped 
back  to  the  “pocher”  again.  The  drained  and  bleached  fibre  is 
afterward  conveyed  to  the  beater  floor  in  trucks,  or  thrown  on 
the  traveling  belt  g,  and  conveyed  to  the  stuff  chest  h,  mixed 
with  water  and  pumped  partly  to  a  wet  machine  on  the  beater 
floor,  to  be. made  into  laps,  and  partly  direct  into  the  beating  en¬ 
gines.  Such  a  system  manifestly  involves  much  labor,  plant  and 
floor  space,  not  to  mention  a  somewhat  large  expenditure  of 
steam  for  heating,  when  hot  bleaching  is  carried  on.  As  a  rule 
not  more  than  2.5  to  3  per  cent  density  of  stock  is  obtained  from 
the  “pocher.” 


Courtesy:  “Paper,”  New  York. 

Fig.  88a. — Tank  system  of  bleaching. 


Bleaching  apparatus  was  next  designed  fulfilling  more  per¬ 
fectly  the  conditions  for  economy.  The  vessels  or  “pochers”  were 
built  of  tile,  or  reinforced  concrete,  and  the  mixture  of  pulp, 
bleach  liquor  and  water,  kept  in  continued  motion  by  means  of  a 
screw  or  propeller,  until  the  process  of  bleaching  was  practically 
completed. 

The  propeller  is  placed  at  one  end,  and  in  this  particular  case 
causes  the  stock  to  travel  in  the  direction  of  the  arrows.  These 
bleaching  engines  are  built  to  hold  from  one  to  ten  tons  of  air-dry 
pulp  per  charge,  and  are  operated  with  from  four  to  six  per  cent 
stock.  Such  a  degree  of  concentration  insures  fair  economy  in 
bleach  and  steam,  but  they  are  intermittent  in  their  action,  and, 
in  consequence,  there  is  considerable  loss  of  time  in  filling  and 
emptying.  The  stock,  after  it  has  acquired  the  right  degree  of 
whiteness,  is  emptied  into  the  chest  beneath,  from  whence  it  is 
pumped  to  the  washing  and  drying  machines.  The  names  of 


210  MODERN  PULP  AND  PAPER  MAKING 

Kellner,  Partington,  Bellmer,  Hromadnick,  and  others  are  identi¬ 
fied  with  bleaching  engines  and  systems  of  this  kind. 

Bellmer  Bleaching  Process. 

Probably  the  most  successful  of  these  systems  is  the  Bellmer 
Bleaching  Process.  The  following  description  of  this  system  is 
furnished  by  die  makers :  The  propellers  are  erected  outside  the 
bleaching  engines  on  a  cast  iron  foundation  plate.  They  are  con¬ 
nected  with  the  engine  tub  by  means  of  flanges  and  enclosed  fun¬ 
nels  projecting  in  the  walls  of  the  tub. 

The  propellers  are  driven  by  a  simple  open  belt  running  from 
above  or  below  the  floor.  When  electric  motors  are  used  the  pro¬ 
peller  axle  is  direct-connected  to  the  motor.  The  frame  can 
easily  be  opened  at  any  time  by  removing  the  top,  and  all  parts 
can  be  easily  removed  for  cleaning  or  inspection. 


Courtesy:  Moore  &■  White  Co.,  Philadelphia,  Pa. 


Fig.  89. — Bellmer  bleach  tanks  showing  propellers. 

_  The  tub  is  generally  made  of  concrete  or  brick  and  is  lined 
inside  with  tile,  these  tiles  requiring  little  cleaning  and  protect¬ 
ing  the^  inside  of  the  tub  from  the  injurious  action  of  the  bleach¬ 
ing  fluid.  Moreover,  the  tile  lining  reduces  the  friction  of  the 
material  against  the  sides  and  bottom  and  helps  to  keep  the  bleach 
liquor  clean.  The  tub  has  no  dead  points  and  is  designed  with 
enough  bottom  fall  to  insure  perfect  circulation.  The  dimensions 
of  the  tubs  can  be  altered  to  suit  local  conditions  and  they  can 
be  installed  singly  or  in  batteries. 

Double  acting  propellers  with  three  running  channels  are  best, 
but  single  acting  propellers  can  be  installed  when  desired  for  in¬ 
stallations  handling  less  than  8,000  pounds  and  are  very  useful 


BLEACHING  211 

for  connecting  up  with  already  existing  bleaching  tubs  of  the 
usual  form. 

The  advantages  of  this  system  are  claimed  to  be  as  follows: 
The  propeller  admits  the  thickest  material  and  will  move  the 
contents  sufficiently  rapidly  to  be  economical.  The  mixing  of  the 
bleaching  liquor  with  the  stock  is  thorough.  Formation  of  scum 
and  knots  is  avoided.  No  separate  stuff  pump  is  required.  Va¬ 
rious  kinds  of  stock  can  be  mixed  while  the  bleaching  operation 
is  going  on. 

It  has  always  been  the  aim  of  pulp  bleachers  to  invent  a 
continuous  system,  or  one  that  is  nearly  so,  and  quite  a  number  of 
such  have  been  constructed  and  operated  for  many  years  in  Eu¬ 
rope  and  America.  Such  plants  are  known  in  Great  Britain  as 
the  “tower  system”  and  in  America  as  the  “continuous  tank  sys¬ 
tem.”  Neither  of  these  fulfills  the  most  perfect  conditions  for 
bleaching,  although  the  tower  system  is  thought  to  be  the  better 
of  the  two.  The  towers  are  usually  concrete  tanks,  with  or  with¬ 
out  conical  bottoms,  connected  together  by  channels  or  passages. 

Continuous  Tank  System. 

This  consists  of  six  or  more  circular  concrete  tanks  12  feet  in 
diameter  by  about  20  feet  deep,  connected  together  with  passages 
or  pipes,  at  top  and  bottom  alternately.  These  tanks  have  flat 
bottoms  and  agitators  driven  by  spur  gearing  at  the  top,  which 
keeps  the  pulp  in  continuous  motion.  The  pipes  or  passages  con¬ 
necting  the  tanks  at  the  bottom,  are  all  on  the  same  level,  but 
those  for  the  overflow  from  2  to  3,  4  to  5,  6  to  7,  and  so  on 
through  the  series,  are  all  on  different  descending  levels,  in  order 
to  permit  the  pnlp  to  flow  by  gravity  from  the  first  to  the  last 
tank  in  the  series  in  the  direction  as  shown  by  the  arrows. 

Instead  of  the  stock  flowing  by  gravity,  it  is  sometimes  pumped 
from  one  tower  to  the  next  in  series.  This  obviously  is  forced 
circulation,  and  has  certain  advantages  over  circulation  by  gravity, 
but  can  scarcely  be  called  a  continuous  system.  It  permits  of 
greater  concentration  of  stock,  a  stronger  bleaching  fluid  in  inti¬ 
mate  contact  with  the  fiber,  and  economy  of  steam  for  heating 
when  hot  bleaching  is  employed,  but  under  the  best  conditions, 
seldom  more  than  4  to  4.5  per  cent  stock  can  be  handled,  which  in 
the  opinion  of  many  is  too  dilute  to  yield  the  most  economical 
results  in  any  continuous  system. 

Skjold^  describes  a  method  of  continuous  bleaching  in  which 
he  employs  a  series  of  flat-bottomed  upright  circular  tanks,  built 
of  concrete  and  containing  agitators,  four  or  more  tanks  being 
employed  in  the  series,  connected  by  an  arrangement  of  pipes,  so 
that  the  pulp  can  be  pumped  from  one  to  the  other  continuously, 
or  circulated  at  will  from  the  bottom  on  the  top  of  each  tank ;  a 
mixing  tank  is  provided  between  the  wet  machine  and  the  first 
bleaching  tank,  for  mixing  the  sheet  of  wet  pulp  with  water  of 

'  Svensk  Pappers-Tidning,  1905,  No.  15,  pg.  85. 


212  MODERN  PULP  AND  PAPER  MAKING 

50°  C.  (122°  F.)  and  bleachinj^  powder  solution  of  3.5°  Be. 
The  bleached  pulp  leaving  the  system  is  washed  on  wet  machines 
before  it  is  dried.  The  tanks  in  this  system  are  each  4.9  meters  in 
diameter  by  8  meters  deep,  giving  a  total  capacity  for  the  four,  of 
about  600  cubic  meters,  and  it  is  stated,  that  from  forty  to  forty- 
five  tons  of  air-dry  pulp  can  be  bleached  in  twenty-four  hours, 
equivalent  to  nearly  500  cubic  feet  of  tank  space  a  ton  a  day. 
This  is  a  large  output,  which  is  made  possible,  perhaps,  by  the 
high  temperature  employed — viz:  from  130°  to  140°  F.  The 
operations  of  this  system  are  somewhat  broken,  and  Beveridge 
states  that  it  is  doubtful  if  these  conditions  as  to  output  could  be 
maintained  in  constant  practice,  unless  the  stock  treated  were  of 
the  easiest  bleaching  character. 

J.  E.  Heiskanen,  in  his  apparatus  (U.  S.  Pat.  1,277,926),  has 
overcome  certain  difficulties  and  has  greatly  simplified  the  con¬ 
tinuous  system.  All  stock  pipes,  centrifugal  pumps  and  agitators, 
are  eliminated,  the  inventor  substituting  for  these  propellers  for 
mixing,  agitating  and  circulating  the  stock  through  the  whole 
system.  These  propellers  are  driven  by  small  motors  and  as  he 
attains  a  density  of  6  to  8  per  cent  stock  he  fulfills  the  best  con¬ 
ditions  for  economy  of  bleach  liquor  and  economy  of  steam  for 
heating.  The  floor  space  occupied  by  the  plant  is  about  half  of 
that  required  for  the  “continuous  tank  system”  mentioned  above. 

The  unbleached  pulp  falls  from  the  pulp  thickener  into  the 
screw  conveyor  where  it  is  mixed  with  the  necessary  quality  of 
bleach  liquor  and  hot  water,  the  mixed  stock  being  conveyed  au¬ 
tomatically  into  the  first  bleaching  tank  la.  The  fiber  in  this 
tank  is  forced  upwards  by  the  propeller  to  the  top  of  Ib,  where 
the  stream  is  divided  by  the  regulating  gates  into  two  parts,  one 
part  giving  back  into  la,  while  the  other  part  flows  into  I  la.  The 
proportion  going  forward  into  I  la  varies  from  one-tenth  to  one- 
fifth  of  the  total  volume  passing  the  propeller,  so  that  the  stock 
in  la  is  kept  circulating  vigorously  and  is  in  continual  motion. 
These  regulating  gates  are  placed  at  the  top  of  Ib,  Ilb,  Illb,  and 
so  on  through  the  whole  series,  the  flow  forward  from  one  tank 
to  another  being  adjusted  by  them  in  accordance  with  the  amount 
required,  and  kind  of  pulp  to  be  bleached.  Steam  is  introduced 
at  the  bottom  of  each  tank  imemdiately  below  the  propeller  to 
maintain  a  uniform  temperature  throughout  the  apparatus. 
After  the  pulp  has  traversed  through  the  series  of  tanks  it  is  dis¬ 
charged  into  the  chest  at  the  end,  from  whence  it  flows  by  gravity, 
or  it  is  pumped,  to  washers  and  finally  to  the  drying  machine. 
The  return  pump  is  not  essential  and  is  seldom  or  never  used,  but 
is  added  to  enable  the  operator  to  pump  the  stock  a  number  of 
tanks  back,  if  by  accident  insufficient  bleach  liquor  has  been 
added. 

Heiskanen  represents  that  his  plant  occupies  half  the  floor 
space  of  the  ordinary  “continuous  tank  system” ;  that  he  can  at¬ 
tain  a  density  of  7  per  cent  stock  on  an  average ;  and  that  by  so 


rt 

biO 


Cl 


& 

o 


^  ra 

^  P 


<a 


rt 

ON 

CO 

_bp 


213 


I 


■l 

4 

yi 

i 


214 


Courtesy:  "Paper,”  New  York. 

Fig.  89b.— Diagram  showing  elevation  of  continuous  tank  system. 


BLEACHING 


215 


doing  the  consumption  of  steam  and  bleach  is  reduced  to  a  mini¬ 
mum.  The  consumption  of  power  and  labor  is  extremely  low  ; 
for  in  the  first  case  there  is  very  little  weight  to  be  moved  by  the 
propellers,  the  columns  of  stock  in  la  and  Ib  equalizing  them¬ 
selves,  while  in  the  second  one  man  is  sufficient  to  run  the  tanks 
from  the  first  tank  to  the  pulp  chest.  He  also  allows  eight  hours 
or  so  for  bleaching  and  completes  this  with  a  total  tank  capacity 
of  about  200  cubic  feet  a  ton  of  pulp  a  day. 

The  plant  as  shown  is  capable  of  handling  100  tons  of  pulp  a 
day,  is  well  designed,  and  as  it  is  constructed  of  concrete,  lined 
internally  with  glazed  tiles  if  so  desired,  and  fitted  with  bronze 
working  parts  in  contact  with  the  fiber,  the  risk  of  iron  spots  ap¬ 
pearing  in  the  dried  pulp  is  avoided. 

Bleach  Consumption. 

The  amount  of  bleach  required  for  any  particular  lot  of  stock 
depends,  as  previously  explained,  on  many  factors.  We  are  of 
the  opinion  that  the  majority  of  mills  use  more  bleach  than  is 
necessary.  There  is  a  tendency  to  use  bleach  liberally,  getting 
rid  of  any  excess  of  bleach  with  antichlor.  This  is  wasteful  and 
expensive. 

Griffin  and  Little  give  the  following  figures  for  the  amount 
of  bleach  required  for  100  lbs.  of  different  fibres : 


Rags . 

Straw . 

Esparto . 

Soda  (poplar) . . . 
Soda  (spruce) .  . . 
Sulphite  (poplar) 
Sulphite  (spruce) 
Jute . 


2  to  5  lbs. 
7  to  10  lbs. 
10  to  15  lbs. 
12  to  15  lbs. 
18  to  25  lbs. 

14  to  20  lbs. 

15  to  25  lbs. 
10  to  20  lbs. 


Use  of  Steam  in  Bleaching. 

Raising  the  temperature  hastens  the  bleaching  process,  but  it 
considerably  increases  the  consumption  of  bleach  as  chlorine  is 
less  soluble  at  the  increased  temperature  and  tends  to  boil  out  of 
the  solution.  Moreover,  too  high  a  temperature  causes  the  bleach 
to  attack  the  cellulose  of  the  fibre  itself,  giving  rise  to  compounds 
which  cause  a  yellow  color  and  a  lessening  of  strength  in  the 
paper. 

Any  economical  system  of  bleaching  must  involve  a  high 
density  of  stock,  primarily  to  economize  steam  for  heating.  This 
is  a  very  important  factor.  The  following  is  Beveridge’s  formula 
for  calculating  the  amount  required,  which  is  applicable  to  every 
case  of  hot  bleaching: 

(W  S  +  W'  S'  +  W"  S"  + . )  (tf  —  ti) 

-  =  s 


T  — tf 


2i6  modern  pulp  and  PAPER  MAKING 

in  which 

S  =  Lb.  of  steam  required. 

W  =  Wt.  of  air-dry  pulp  in  the  charge,  in  lb. 
s  =  Sp.  heat  of  air-dry  pulp  (0.65). 
w'  Wt.  of  water  associated  with  the  pulp  in  lb. 
s'  =  Sp.  heat  of  water  (i.oo). 

w"  =  Wt.  of  vessel  in  which  pulp  is  bleached,  in  lb. 
s"  =  Sp.  heat  of  material  of  which  w"  is  constructed, 
ti  =  Initial  temperature  of  stock  in  degrees  Fahr. 
tf  =  Final  temperature  of  stock  in  degrees  Fahr. 

T  =  Total  B.  thermal  units  in  i  lb.  of  steam  used  for  heating. 

From  this  formula  the  following  quantities  of  steam  required 
for  different  densities  of  stock  bleached  at  different  temperatures 
have  been  calculated,  taking  the  initial  temperature  t,  as  60° 
F.,  the  final  temperature  tf,  as  90,  100,  no  and  120°  F.,  and  the 
total  British  thermal  units  in  one  pound  of  steam  T  as  1,190, 
i.  e.,  steam  at  no  lbs.  pressure  above  atmospheric. 

Density  of  Water  associ-  Lbs.  of  steam  required  to  heat  the 

stock  ated  with  2000  lb.  ^  mixture  containing  2000  lb.  air-dry 

Pulp  Water  air-dry  pulp  pulp  to 

90°  F.  100°  F.  1 10°  F.  120°  F. 


3% 

97% 

64,666  lb. 

1881 

2421 

3053 

3699 

4% 

96% 

48,000  lb. 

1427 

1809 

2282 

2764 

5% 

95% 

38,000  lb. 

1154 

1442 

1819 

2203 

6% 

94% 

3L333  lb. 

972 

1197 

1510 

1830 

7% 

93% 

26,571  lb. 

842 

1023 

1290 

1562 

8% 

92% 

23,000  lb. 

745 

892 

1125 

1269 

Note:  This  table  is  based  on  the  above  formula  but  the  weight  of  the  appa¬ 
ratus  w"  has  been  eliminated.  Three  per  cent  should  be  added  to  the  above 
quantities  of  steam  in  cols.  4,  5,  6  and  7  to  allow  for  loss  of  heat  by  radiation. 


Antichlors. 

The  complete  removal  of  surplus  bleach  by  washing  being  a 
very  slow  operation,  many  mills  remove  the  last  traces  of  bleach 
with  an  antichlor.  The  ordinary  antichlor  is  hyposul])hite  of 
soda  or  sodium  thiosulphate  (which  are  just  two  names  for  the 
same  chemical).  Sodium  sulphite,  calcium  sulphite  and  sulphite 
waste  liquor  have  been  used  also  as  antichlors. 

Blueing. 

A  small  amount  of  blue  (ultramarine  or  some  other  blue)  is 
frequently  added  to  offset  any  slight  yellowness  that  may  be  left 
after  bleaching.  Sometimes  this  is  done  with  pulp  that  is  to  be 
offered  for  sale  to  cover  up  imperfect  bleaching.  The  addition 
of  even  very  little  blue  soon  becomes  apparent  to  the  eye  of  the 
expert.  It  can  best  be  detected  by  rolling  a  lap  of  the  pulp  into 
a  tube  and  looking  into  it  by  a  clear  north  light,  or  by  looking 
into  a  folded  lap  as  into  the  pages  of  a  half  open  book. 


BLEACHING 


217 


Use  of  Acid  in  Bleaching, 

Some  paper  makers  add  a  little  sulphuric  or  other  acid  in 
bleaching.  This  is  often  alluded  to  as  “souring.”  The  acid  is 
generally  added  towards  the  latter  stages  of  the  bleach  when  the 
stock  has  almost  reached  the  required  degree  of  whiteness.  The 
action  of  the  acid  is  that  it  neutralizes  the  lime  salts  and  facilitates 
the  liberation  of  chlorine.  Probably  the  chemist  would  consider 
the  above  explanation  inadequate,  but  the  chemistry  of  this  proc¬ 
ess  is  really  quite  complicated.  The  above  is,  however,  the  gen¬ 
eral  effect.  Acetic  acid  is  considered  less  harmful  to  the  stock 
than  mineral  acids,  and  for  that  reason  is  favored  by  some  paper 
makers. 

Electrolytic  Bleach. 

Many  paper  mills  have  introduced  electrolytic  plants  for  the 
production  of  their  own  bleach.  It  is  beyond  the  scope  of  this 
work  to  explain  in  detail  the  construction  and  operation  of  such 
plants,  which  is  really  more  a  matter  for  chemical  and  electrical 
engineers  than  for  paper  makers.  However,  very  simple  and 
efficient  installations  have  been  designed  which,  when  once  in¬ 
stalled,  can  be  operated  by  the  usual  force  of  a  paper  mill  without 
any  special  skilled  attention. 

There  are  a  number  of  cells  on  the  market  for  this  purpose, 
of  which  the  Allen-Moore,  Nelson  and  Wheeler  are  excellent  ex¬ 
amples.  They  all  operate  by  allowing  an  electric  current  to  pass 
through  a  solution  of  common  salt,  decomposing  it  into  chlorine 
and  hydrogen.  In  all  but  a  few  very  large  plants  the  hydrogen 
is  allowed  to  go  waste.  One  large  paper  mill  in  New  England 
uses  the  hydrogen  to  hydrogenate  oils  and  to  make  hydrochloric 
acid  which  they  sell.  This  is  an  example  of  what  can  be  done  in 
the  way  of  utilizing  by-products.  The  chlorine  is  led  into  vessels 
where  it  reacts  with  milk-of-lime  to  form  bleach  liquor  which  is 
used  directly  in  the  bleaching  process.  Caustic  soda  is  also  pro¬ 
duced  as  a  by-product,  and  if  no  use  can  be  found  for  this  in  the 
mill  it  can  be  concentrated  and  sold. 

Another  type  of  cell  does  not  separate  the  products  of  the 
electrolytic  action  and  produces  sodium  hypochlorite  liquor,  which 
is  used  as  bleach  instead  of  bleaching  powder  solution. 

Many  pulp  and  paper  mills  being  located  where  water  power 
is  plentiful  and,  in  consequence,  electric  current  comparatively 
cheap,  and  being  distant  from  points  where  bleaching  powder  is 
manufactured,  find  the  manufacture  of  their  own  bleach  a  very 
profitable  proposition. 

Bleaching  Ground  Wood. 

The  bleaching  of  ground  wood  is  a  very  difficult  matter  as  this 
class  of  pulp  contains  all  the  intracellular  matter  of  the  original 
wood.  Moreover,  there  has  been  little  demand  for  this  product 


2I8 


Typical  cell  for  manufacturing  electrolytic  bleach. 


BLEACHING 


Courtesy:  Swenson  Evaporator  Company,  Chicago,  III. 

Pig.  91 — Type  of  evaporator  used  for  concentrating  caustic  soda  produced 
as  a  by-product  in  the  manufacture  of  electrolytic  bleach. 

bleaching  solution  is  sprayed  by  this  pipe  evenly  on  the  upper  roll, 
from  that  it  is  transferred  to  the  lower  of  the  two  small  rolls,  the 
intention  in  this  arrangement  being  to  equalize  the  distribution  of 
the  bleach,  and  from  the  lower  small  roll  to  the  sheet  of  pulp 
that  is  winding  up  on  the  top  press  roll.  Difficulty  has  been  met 
with  owing  to  the  perforations  in  the  pipe  clogging  up.  A 


219 


in  America.  In  Europe,  however,  the  bleaching  of  ground  wood 
has  developed  to  quite  an  extent.  The  bleaching  agent  is  sodium 
bisulphite  and  the  operation  is  carried  out  on  a  wet  machine,  the 
top  press  roll  of  which  is  equipped  with  two  small  felt  covered 
rolls.  Above  the  upper  roll  is  a  hard  lead  spray  pipe.  The 


220 


MODERN  PULP  AND  PAPER  MAKING 

patent  distributing  box  intended  to  overcome  this  difficulty  has 
been  invented  by  Schutz  (U.  S.  P.  1,208,670).  The  sodium 
bisulphite  is  used  in  2  or  3  per  cent  solution. 

Bleached  ground  wood  is  never  as  bright  and  white  as 
bleached  sulphite.  It  can  always  be  detected  in  paper  very  easily 
as  the  bleaching  does  not  prevent  the  fibre  from  showing  the  usual 
deep  red  coloration  characteristic  of  ground  wood  with  phloro- 
glucinol. 

Bleached  ground  wood  has  found  its  chief  application  in  light 
weight  papers  where  opacity  is  desired.  It  will  increase  the 
opacity  without  decreasing  the  tensile  strength  as  much  as  a  suffi¬ 
cient  quantity  of  filler  to  produce  the  same  result  would. 

For  ground  wood  for  bleaching  dull  stones  and  high  pressure 
should  be  used,  but  this  should  not  be  carried  so  far  as  to  unduly 
decrease  production.  In  Austria  excellent  tissue  paper  is  being 
made  from  30  per  cent  bleached  rag,  30  per  cent  bleached  sulphite 
and  40  per  cent  bleached  ground  wood.  It  has  also  been  used  for 
cheap  book  and  magazine  papers. 


I 


XII.  The  Beater  Room. 

The  manufacture  of  paper,  as  distinct  from  the  manufacture 
of  pulp,  starts  m  the  beater  room.  In  studying  the  preceding 
sections,  dealing  with  the  various  processes  for  making  pulp  it 
should  always  have  been  kept  in  mind  that  pulp  is  not  paper— it 
IS  merely  one  of  the  raw  materials  of  paper,  of  which  there  are  a 


Fig.  92. — Typical  beater  room. 


number  of  others  of  lesser  importance,  e.  g.,  clay,  size,  colors,  etc. 
1  nere  are  rnany  large  paper  mills  which  do  not  manufacture  any 
pulp  at  all  buying  all  their  raw  material  from  other  plants  which 

stop  with  the  manufacture  of  pulp  and  do  not  proceed  to  make  it 
into  paper. 

Beaters. 

The  beaters,  or  beating  engines,  are  lar^e,  oval,  tank-like  ma¬ 
chines  constructed  of  3  or  4  inch  cypress  or  other  suitable  planks. 

221 


Courtesy :  E.  D.  Jones  &  Sons  Co.,  Pittsfield,  Mass. 

Fig.  94. — Iron  tub  beater. 

The  dimensions  vary  according  to  the  requirements.  The  fol¬ 
lowing  is  a  table  of  the  sizes  and  dimensions  of  the  beaters  made 
by  one  prominent  American  manufacturer  of  these  machines : 


Approximate  Dimensions  and  Capacities  of  Beaters 


Length 

Width  of  Tank 

Size  of  Roll 

Capacity  lbs. 

R.P.M. 

is'  6" 

6'  6" 

36" X  34” 

300 

Bis 

17'  6" 

6'il' 

40" X  36" 

500 

148 

17'  6" 

6'ii" 

54"  X  36" 

500 

1 10 

18'  0" 

7'  8" 

40" X  40" 

600 

148 

17'  6" 

7'  8" 

54" X  40" 

600 

1 10 

18'  0" 

8'  3" 

44"  X  44" 

800 

135 

19'  6" 

7'ii" 

58"  X  42" 

800 

102 

21'  7" 

8'ii" 

48"  X  48" 

1000 

124 

21'  7" 

8'ii" 

62"  X  48" 

1000 

96 

21'  7" 

8'ii" 

54" X  48" 

1200 

1 10 

23'  0" 

9'  7" 

65"  X  52" 

1200 

91 

23'  8" 

10'  5" 

58" X  56" 

1500 

102 

24'  8" 

10'  9" 

67"  X  58" 

1500 

88 

24'  2" 

10'  5" 

62"  X  56" 

1600 

96 

24'  8" 

10'  9" 

72"  X  56" 

1600 

82 

25'  8" 

ii'  2" 

60"  X  60" 

1800 

99 

26'  2" 

ii'  2"  , 

72"  X  60" 

1800 

82 

26'  8" 

ii'  6" 

62"  X  62" 

2000 

96 

27'  9" 

12'  2" 

72" X  66" 

2000 

82 

Courtesy:  E.  D.  Jones  &  Sons  Co.,  Pittsfield,  Mass. 

Fig-  9.3- — Wood  tub  beater. 


222 


MODERN  PULP  AND  PAPER  MAKING 


I 


THE  BEATER  ROOM  223 

A  usual  size  is  about  25  feet  long  by  ii  feet  wide.  Such  a 
beater  will  hold  about  1,500  pounds  of  completed  stock.  The 
usual  height  of  the  walls  of  .  the  beater  is  about  feet. 

Some  beaters  are  constructed  of  iron,  having  cast  iron  or  steel 
plate  sides  and  ends,  and  a  bottom  of  wood,  cast  iron  or  concrete. 
Concrete  beaters  are  also  used.  In  such  cases  the  customer  fur¬ 
nishes  the  concrete  construction  and  the  roll,  bearings,  bed-plate 
and  various  fittings  are  supplied  by  a  manufacturer. 

Extending  through  the  middle  of  the  tank,  parallel  with  the 
sides,  but  stopping  short  of  the  ends  by  about  three  feet,  is  a 
sturdy  fence-like  partition  called  the  midfeather.  The  mid- 


SCCT/MAt  VtC¥t 


big-  95- — Diagram  showing  side  and  end  elevation  of  typical  beater. 


feather  may  be  of  either  wood  or  iron.  On  one  side  of  the  tank, 
filHng  the  space  between  the  midfeather  and  the  wall,  is  a  cylin¬ 
drical  beater  roll.^  This  roll  is  so  proportioned  that  its  diameter 
is  about  equal  to  its  length,  the  exact  dimensions  varying  with  the 
size  of  the  beater,  an  idea  of  this  being  given  by  the  preceding 
table.  This  roll  is  equipped  with  78  steel  bars  or  knives,  each 
about  8  inches  wide  and  ^  to  inch  thick.  At  the  bottom  of 
the  tank,  directly  under  this  foil  is  a  bed-plate,  extending  the  full 
width  of  the  roll  and  shaped  so  that  its  upper  surface  is  parallel 
with  the  surface  of  the  roll.  The  bed-plate  is  usually  about  16 
inches  wide  and  5  inches  high  and  it  contains  42  knives.  These 
knives  are  not  set  exactly  parallel  with  the  knives  of  the  roll. 
They  are  usually  arranged  at  an  angle  or  in  a  V-shaped  arrange¬ 
ment,  as  shown  in  the  illustration. 

The  details  of  the  construction  of  the  roll  and  bed-plate  will  be 
dealt  with  later  in  this  chapter  under  the  heading  “Maintenance 


224 


MODERN  PULP  AND  PAPER  MAKING 


of  Beater  Room  Equipment.”  Such  a  beater  as  we  have  de¬ 
scribed  is  frequently  spoken  of  as  a  Hollander  or  Holland  type 
beater.  Other  special  types  of  beater  departing  widely  from  the 
above  description,  but  intended  for  the  same  purpose,  have  been 
designed.  A  few  of  the  more  important  of  these  will  be  de¬ 
scribed  later,  but  the  above  description  covers  the  usual  type  of 
beater  in  ’paper  mills  throughout  the  world. 

When  the  beater  roll  revolves  each  of  its  78  roll  bars  or 
knives  comes  in  contact  with  each  of  the  42  knives  of  the  bed¬ 
plate,  so  that  the  roll  will  give  3,276  cuts  for  each  revolution.  ^ 

With  the  roll  running  at  a  speed  of  100  revolutions  per  min¬ 
ute,  it  is  apparent  that  there  will  be  delivered  327,600  cuts  per 
minute  to  any  material  forced  between  the  roll  and  the  bed¬ 
plate. 

The  beater-roll  weighs  several  tons  and  may  be  raised  from,  or 
lowered  upon,  the  bed-plate  by  “Lighter-Bars,”  which  carry  the 
roll  in  strong  journals.  Such  movement  is  rendered  very  accu¬ 
rate  by  having  a  hand  wheel  geared  to  it  in  a  pretty  large  ratio. 
Thus  the  roll  may  be  changed  in  its  relation  to  the  bed-plate  a 
very  small  fraction  of  an  inch.  These  fine  adjustments  are  fre¬ 
quently  necessary. 

Into  the  beater  the  beater  help  feed  the  various  ingredients  of 
the  paper  as  determined  by  the  “Formula.”  When  it  has  been 
found  by  experience  that  a  certain  percentage  of  sulphite  pulp,  a 
certain  percentage  of  Kraft  (sulphate)  pulp  or  of  ground  wood, 
so  much  coloring  matter,  so  much  “fixing”  solution,  size,  filler, 
etc.,  is  required  to  produce  a  certain  definite  grade  of  paper,  these 
percentages  are  rigidly  adhered  to  every  time  a  run  of  this  paper 
is  made. 

Naturally,  such  measurements  and  chemical  treatment  cannot 
be  carried  out  by  guesswork.  The  percentage  of  the  various  in¬ 
gredients  are  reduced  to  terms  of  weight  (the  various^ pulps,  sul¬ 
phite,  sulphate  and  ground  wood  being  fixed  on  a  “5  per  cent 
air-dry”  basis)  and  the  “Furnish”— this  being  the  phrase  by 
which  the  exact  formula  of  a  given  grade  of  paper  is  known 
is  built  up  accurately  on  exact  scales. 

When  a  large  mass  of  pulp  is  placed  in  the  vat  (which  is  ca¬ 
pable  of  holding  1,500  pounds  of  completed  paper-stock)  the  re¬ 
volving  of  the  roll  will  draw  the  material  between  itself  and  the 
bed-plate  and  cause  a  general  circulation  of  the  material,  around 
and  around  the  tank,  since  the  midfeather  gives  us  a  perfectly 
oval  path  for  the  “stuff”  to  travel  in. 

Sand  Trap:  A  short  distance  in  front  of  the  roll,  a  small 
box  or  trough  extending  from  the  side  of  the  beater  to  the  mid¬ 
feather  is  set  in  the  floor  of  the  beater.  This  trough  is  covered 
with  a  screen  plate.  It  is  known  as  a  sand-trap  and  it  serves  to 
eliminate  small  particles  of  grit  and  dirt  which,  on  account  of 
their  weight,  stick  to  the  bottom  of  the  stock  as  it  circulates 
around  the  beater.  This  is  used  only  for  fine  papers. 


THE  BEATER  ROOM 


225 

Backfall:  As  the  beater-roll  turns  up  the  material  rather 
sharply  behind  it,  a  cover  or  decking  is  necessary  at  that  part, 
and  a  little  beyond,  to  hold  the  mass  down  to  its  proper  level 
and  prevent  its  being  thrown  out  of  the  beater.  Immediately 
behind  the  beater-roll  is  a  device  known  as  the  “Backfall.”  This 
is  a  hump  or  elevation  constructed  of  wood  covered  with  steel 
plate,  the  side  of  which  nearest  to  the  beater-roll  conforms  in 
shape  to  the  roll.  The  pulp  is  propelled  upwards  between  the 
beater-roll  and  the  backfall  and  strikes  the  cover  of  the  beater 
which  gradually  smooths  out  the  flow  so  that  the  pulp  again  be¬ 
comes  level  in  its  travel  around  the  beater  before  coming  under 
the  beater-roll  the  next  time.  The  tendency  to  mount  up  and 
overflow  behind  the  beater-roll  is  much  more  marked  in  the  case 
of  the  heavy  viscous  stocks — such  as  those  containing  a  high 
percentage  of  Kraft  pulp. 

Doctor:  Immediately  above  the  backfall  and  behind  the  roll 
is  a  doctor  consisting  of  a  heavy  board  with  a  cast  iron  edge. 
This  doctor  is  arranged  so  as  to  just  clear  the  surface  of  the  roll 
and  prevent  any  stock  being  carried  around  with  the  roll,  deflect¬ 
ing  it  back  over  the  top  of  the  backfall. 

String  Catchers:  In  beating  certain  classes  of  stock  such  as 
waste  paper,  jute,  etc.,  strings,  rope,  wire,  etc.,  are  frequently 
present.  The  string  catcher  is  a  device  consisting  of  a  series  of 
bars  or  fingers  secured  to  a  steel  shaft  which  extends  over  the 
path  of  the  stock  in  the  beater.  The  shaft  and  fingers  form  a 
sort  of  fork  or  rake  which  will  catch  any  pieces  of  string  or  rope 
without  seriously  impeding  the  flow  of  the  stock.  A  hand  wheel 
is  provided  by  means  of  which  the  device  can  be  raised  or  low¬ 
ered,  as  required.  This  device  not  only  prevents  string  and  rope 
from  being  mixed  with  the  stock  but  also  prevents  such  material 
from  winding  around  the  beater  shaft  where  it  would  cause  a 
great  deal  of  trouble. 

Emptying  and  Wash-Out  Valves:  Various  arrangements  are 
used  for  emptying  the  stock  from  the  beater.  One  of  the  com¬ 
monest  is  an  iron  disc  resting  on  a  circular  seat.  In  the  center 
is  a  depression  spanned  by  a  cross-bar  by  means  of  which  the  disc 
is  lifted  out  of  its  seat,  allowing  the  stock  to  flow  out  of  the 
beater.  This  device  has  the  objection  that  the  opening  is  relatively 
small,  thus  increasing  the  time  necessary  to  empty  the  beater. 
Moreover,  if  any  pressure  is  created  in  the  stock  chest,  for  in¬ 
stance,  when  one  or  more  other  beaters  are  being  emptied,  the 
disc  may  be  forced  up,  allowing  the  contents  of  the  beater  to 
be  prematurely  dumped.  This  is  guarded  against  sometimes  by  a 
lock  type  of  valve,  as  illustrated.  However,  this  is  no  more 
rapid  in  operation  than  the  ordinary  type  and  involves  fumbling 
with  a  locking  device  at  the  bottom  of  a  beater  full  of  stock. 

Much  better  are  special  quick-emptying  valves,  which  are 
operated  by  a  lever  outside  the  beater.  The  disc  is  carried  on  a 
riser  operated  by  a  series  of  levers.  A  spray  of  water  is  also 


226  MODERN  PULP  AND  PAPER  MAKING 

provided  with  this  type  of  valve  which  assists  in  the  rapid  re¬ 
moval  of  the  stock  and  also  keeps  the  valve  seat  clean  and  free, 

A  still  further  improvement  is  a  patented  stock  emptying 
valve  of  oblong  shape  about  6  inches  wide  located  in  the  bottom 
of  the  engine  just  in  front  of  the  roll,  extending  right  across 
from  the  midfeather  to  the  side  of  the  beater,  its  top  being 
flush  with  the  bottom  of  the  inside  of  the  engine.  The  valve 
cover  lifts  up  along  the  side  furthest  from  the  roll,  and  when 
raised  to  a  vertical  position  becomes  a  dam,  aiding  in  forcing 
the  stock  out  of  the  beater.  It  is  operated  by  a  shaft  extending 
through  the  side  of  the  beater  and  having  a  lever  at  its  outer 
end.  A  shower  of  water  is  provided  to  help  the  stock  out  of 
the  beater  and  to  keep  the  valve  seat  clean.  With  an  adequate 


Courtesy :  Noble  &  Wood  Machine  Co.,  Hoosick  Falls,  N.  Y. 

Fis-  97- — r)i.sc  type  of  emptying  valve  for  beater. 

discharge  pipe  (not  less  than  i8  inches  diameter),  the  stock 
can  be  removed  from  the  beater  almost  instantly  without  using 
any  rakes  and  with  a  minimum  of  labor.  With  the  ordinary 
disc  valves  the  use  of  rakes  is  generally  imperative. 

Function  of  the  Beater. 

Referring  to  the  roll  and  bed-plate  of  the  beater  as  containing 
“knives”  may  possibly  have  caused  the  reader  to  think  that  the 
main  purpose  of  this  machine  is  to  cut  the  fibres  to  a  given 
length.  While  the  machine  admittedly  is  used  for  this  purpose, 
this  is  not  its  only  function — or  its  most  important  one.  No  less 
cital  than  the  cutting  of  the  fibres  to  a  certain  length  is  the  sepa¬ 
rating  of  the  bundles  of  fibres  (which  will  exist  to  a  certain  ex¬ 
tent  in  even  the  best  grades  of  sulphite  and  kraft  pulps)  and  to 
brush  or  stroke  the  fibres  into  greater  flexibility. 

The  tiny  fibres  are  stroked  out  by  the  blunt  knives  of  the 
beater,  in  somewhat  the  same  manner  that  a  hairbrush  strokes  out 
human  hair,  and  moreover  the  fibres  are  caused  to  curl  at  the 
ends. 


THE  BEATER  ROOM 


227 


Upon  the  ability  of  these  fibres  to  curl  and  connect  with  each 
other,  when  allowed  to  “bond”  (by  removal  of  the  surrounding 
liquid)  depends  the  strength  and  toughness  of  the  resulting  paper. 
If  these  fibres  are  not  drawn  out  to  the  correct  degree,  they  will 
not  grasp  and  entwine  with  each  other  in  the  manner  which  we 
denote  by  the  term  “felting.” 

It  will  readily  be  appreciated  that  not  only  must  the  fibres  be 
“brushed  out”  and  made  flexible,  but — in  order  to  obtain  a  sheet 
which  will  have  strength  and  thickness — the  fibres  must  be  kept 
long  in  the  beater.  This  applies  with  particular  emphasis  to  pa¬ 
pers  of  light  basis-of-weight,  of  which  a  great  deal  is  expected — 
as,  for  example,  fine  writings,  ledger  and  bond  papers  and  28- 
and  30-pound  kraft  wrapping  and  bag  papers. 

Now,  if  we  are  to  have  a  consistent  length  maintained,  it  will 
be  seen  that  (whatever  its  shape  and  size)  a  beating  engine  must 
be  smoothly  constructed  so  that  no  stuff  can  lodge  and  stay  in 
any  part  of  it,  but  must  circulate  uniformly  around  and  around, 
and  beneath  the  roll  again  and  again.  Fillets  are  provided  in  the 
angle  between  the  sides  and  bottom  of  the  beater  so  that  no  stuff 
can  lodge  and  remain  in  a  position  where  it  does  not  come  under 
the  action  of  the  beater-roll,  as  might  be  the  case  if  the  sides  and 
bottom  of  the  beater  joined  at  a  sharp  angle. 

Moreover,  the  roll  must  be  heavy  enough  to  soften  thoroughly 
all  pulp  and  keep  it  in  constant  motion.  Another  great  desira¬ 
bility  in  a  beater,  is  to  be  able  to  adjust  it  so  minutely  as  to  give 
us  the  exact  length  and  quality  of  fibre  we  desire — and  to  main¬ 
tain  the  entire  output  completely  uniform. 

While  we  have  stated  that  long  fibres  are  vital  in  certain 
classes  of  paper,  it  is  equally  important  that  we  must  not  have 
them  too  long.  Else  the  paper  produced  will  actually  possess  less 
firmness  and  tensile  strength  than  if  the  fibres  had  been  a  little 
shorter.  This  is  true  because  of  the  paper  machine’s  inability  to 
mesh  and  quickly  drain  paper-stuff  containing  fibres  that  are  be¬ 
yond  a  certain  length.  This  point  will  become  clearer  after  we 
have  discussed  the  construction  and  operation  of  the  paper  ma¬ 
chine. 

But,  whether  the  fibres  are  to  be  long  or  short  when  they 
reach  the  paper  machine,  the  basic  properties  of  the  paper  will 
depend  on  the  treatment  they  receive  during  the  first  hour  and  a 
half  in  the  beater.  If  the  roll  be  put  down  sharply  on  the  plate 
at  first,  the  fibres  may  retain  their  length,  but  they  will  be 
considerably  weakened,  and  the  sheet  will  have  a  raw,  soft  feeling. 
Such  stuff  is  generally  termed  “fast”  or  “free.” 

In  brief,  the  beater  is  not  an  automatic  machine.  It  is  an 
instrument — and  one  that  requires  intelligent  and  experienced 
control.  An  inexperienced  or  careless  operator  can  easily  ruin 
an  entire  charge  of  material — especially  during  the  first  hour 
and  a  half. 

The  “rawness”  alluded  to  above  as  caused  by  putting  the  roll 


228 


MODERN  PULP  AND  PAPER  MAKING 


too  sharply  down  on  the  plate  at  first,  is  often  quite  noticeable 
in  papers  made  from  kraft  pulp.  In  the  thin  papers  of  this 
class,  the  idea  that  length  of  fibre  necessarily  means  strength 
is  so  often  over-stressed  that,  when  the  pulp  reaches  the  paper 
machine,  a  considerable  portion  of  it  refuses  to  drain  properly. 
The  whole  matter  (as  intimated  above)  lies  in  the  fact  that  a 
great  part  of  the  worth  of  the  resulting  sheet  of  paper  is  con¬ 
tingent  upon  the  behavior  of  the  fibres  in  meshing  readily  on  the 
paper  machine. 

Under  a  microscope,  a  sheet  of  thin  paper  will  often  exhibit 
spaces  between  the  long  fibres,  which  seem  to  be  filled  with  a 
transparent,  non-fibrous  material.  The  longer  the  fibres,  the 
more  apparent  these  spaces  will  be — and,  however  minute,  their 
presence  must  tend  to  weaken  the  sheet.  With  fibres  just  a  shade 
finer,  the  finest  of  all  will,  on  the  paper  machine,  tend  to  settle 
into  these  spaces,  more  closely  felting  the  whole  sheet. 

So  that,  while  as  a  general  proposition  the  long  fibre  does 
lend  the  sheet  its  great  strength,  it  should  be  borne  in  mind 
that  this  is  not  the  entire  value — and  that  good  stock  for  light, 
strong  papers  requires  a  certain  free  fibre  to  be  present  as  well. 
This  will  be  explained  in  greater  detail  when  we  come  to  talk 
of  the  paper  machine,  but  it  is  necessary  to  allude  to  the  fact 
now  in  order  to  illustrate  the  problems  that  arise  in  the  proper 
handling  of  the  equipment  of  the  beater  room. 

On  the  other  hand,  in  preparing  stuff  for  thick  papers,  the  roll 
can  be  put  down  much  sooner  after  the  beater  has  been  furnished. 
This  is  so  that  the  stuff  may  be  fine  and  free,  parting  with  water 
readily  on  the  paper  machine,  and  giving  a  close,  easily  felted 
sheet.  But  there  is  danger  here  in  going  to  extremes  and  making 
the  stuff  too  soft  and  fine,  so  that  we  must  not  run  it  too  long 
in  the  beater. 

Blunt  plates  and  rolls  are  used  for  stock  intended  for  thin, 
strong  papers  which  must  be  kept  in  the  beater  for  at  least  six 
hours,  during  which  time  sharp  knives  would  cut  it  up  altogether 
too  much  (making  it  too  free)  and  preventing  it  from  felting 
properly  on  the  machine.  For  preparing  such  stock  the  Jordan 
and  other  engines,  subsequently  to  be  described,  are  very  useful, 
the  stock  being  beaten  a  shorter  time  and  finished  in  the  Jordan. 
In  the  thick,  heavy  papers  sharper  plates  and  rolls  may  be  used, 
and  the  stock  is  not  held  nearly  so  long  in  the  beater.  For  in¬ 
stance,  stock  for  blottings  is  frequently  only  kept  in  the  beater 
an  hour  and  a  half. 

From  the  above  considerations  the  reader  will  be  able  to  under¬ 
stand  why  the  beating  time  varies  over  such  a  wide  range  in  pre¬ 
paring  stuff  for  different  grades  of  paper,  ranging  all  the  way 
from  merely  mixing  the  stock  and  color  and  then  dumping  in 
thirty  minutes,  to  combing  out  and  beating  for  eight  hours  or 
more. 

When  a  large  proportion  of  ground  wood  is  involved,  (as 


THE  BEATER  ROOM 


229 

is  the  case  with  some  of  the  cheaper  varieties  of  bag  paper,  etc.), 
the  beaters  must  not  be  heavily  loaded  (that  is,  only  a  compara¬ 
tively  small  amount  of  stuff  can  be  handled  in  one  batch),  nor 
allowed  to  run  very  long,  since  this  class  of  fibre  is  naturally 
reduced  very  quickly,  and  soon  arrives  at  the  state  known  among 
paper-makers  as  “slow  stuff” — that  is,  not  draining  quickly  and 
properly  on  the  paper  machine,  which  is  conducive  to  poor  quality 
and  cuts  down  the  productive  efficiency  of  the  paper  machines 
seriously. 

When  excellent  folding  qualities  are  especially  desired — for 
instance,  in  paper  to  be  used  for  the  manufacture  of  bags — 
the  beating  time  is  protracted,  but  under  these  circumstances 
the  roll  is  lowered  only  enough  to  give  a  very  gentle  rub. 

It  is  always  preferable  to  use  separate  beating  engines  for 
the  extremes  of  adjustment  illustrated  above.  Or,  in  other  words, 
the  beater  that  is  used  for  greasy  slow  stuff  should  not  be  used 
for  short  ground  wood  fibres.  With  even  the  most  careful  manip¬ 
ulation  and  adjustment,  there  is  a  certain  range  over  which  a 
beating  engine  operates  most  efficiently. 

Notwithstanding  the  degree  of  nicety  with  which  (by  means 
of  the  hand-wheel  geared  to  the  lighter-bars),  the  roll  can  be 
raised  or  lowered,  regulating  very  minutely  the  superficial  pres¬ 
sure  exerted  on  the  ultimate  fibres,  the  stuff  produced  with  sharp 
bars  is  inevitably  weaker  (even  if  the  ultimate  fibres  be  of  full 
length)  and  it  will  lack  the  greasy,  well-beaten  feel,  indispensable 
in  the  production  of  thin,  tough  papers. 

Moreover,  long  experience  has  demonstrated  that  a  light 
beater-roll  will  draw  out  fibres  much  better  than  a  heavy  one, 
even  though  it  takes  longer  to  do  it.  The  crux  of  the  whole 
matter  is  the  superficial  pressure  exerted  on  the  fibres  by  the 
beater-roll — since,  with  sharp  bars,  the  pressure  is  increased  in 
proportion  as  the  area  of  the  bearing-and-cutting  surf  ace  is  re¬ 
duced. 

Consequently,  it  is  necessary  to  determine  the  type  of  the 
beater  engine  in  accordance  with  the  special  requirements  of  the 
paper  it  is  desired  to  produce,  whether  this  be  newsprint,  writing 
paper,  bag  paper,  etc. 

In  the  manufacture  of  some  grades  of  newsprint,  with  a 
large  percentage  of  ground  wood,  a  treatment  in  agitators  some¬ 
times  precedes  the  treatment  in  the  beater.  These  agitators  are 
simply  large  tanks  provided  with  mechanically  driven  stirrers 
to  keep  the  stock  in  circulation.  The  pulp  is  treated  with  size 
and  alum,  and  held  in  the  agitator  sufficiently  long  for  the  size 
and  alum  to  penetrate  the  fibres.  This  is  called  “soft  stock”  as 
opposed  to  sulphite,  which  is  “medium  stock,”  and  kraft  would 
be  a  good  example  of  “hard  stock.” 

Numerous  forms  of  testing  instruments  have  been  devised 
for  determining  the  control  of  the  beater  operation,  but  the  human 
element  still  governs  it  to  a  high  degree.  The  appearance  of  the 


230  MODERN  PULP  AND  PAPER  MAKING 

stock  in  the  beater  and  the  feel  when  a  handful  of  it  is  picked  up 
are  the  chief  points  on  which  the  experienced  operator  relies. 

Even  the  novice,  if  of  an  observing  nature,  will  notice  that 
when  the  stock  is  first  admitted  to  the  beaters,  it  is  cold,  bulky 
and  fills  the  beater  to  the  brim.  This  appearance  will  be  kept  up 
for  some  time,  the  stock  breaking  at  various  intervals,  just 
before  it  passes  under  the  beater  roll.  As  the  operation  proceeds, 
however,  there  is  a  slight  rise  in  temperature,  the  stock  tends 
to  sink  more  to  the  bottom,  and  at  intervals  it  will  shine  on  the 
surface. 

After  the  stock  has  been  worked  in  the  beater  it  has  a  char¬ 
acteristic  feeling,  quite  different  from  that  of  unworked  stock. 


Courtesy:  Noble  &  Wood  Machine  Co.,  Hoosick  Falls,  N.  Y. 

Fig.  96. — Beater  hydrant. 

The  hand  will  pass  through  it  freely  and  it  will  be  slippery  and 
“greasy”  so  that  it  is  practically  impossible  to  retain  any  large 
amount  in  the  hand  when  squeezed.  An  experienced  paper- 
maker,  by  taking  up  a  handful  of  stock  in  a  beater,  can  generally 
tell  how  long  the  stock  has  been  beaten,  and  how  long  it  will 
still  have  to  go,  from  the  feeling  alone,  even  if  he  has  no  other 
source  of  information. 

As  the  treatment  the  stock  requires  in  the  beater  depends 
extensively  on  how  it  has  been  cooked  in  the  digester,  it  is  not 
possible  for  the  workman  in  charge  of  the  beater  to  operate 
under  any  fixed  rule.  Consequently,  he  must  be  a  man  of  ex¬ 
perience  and  good  judgment.  Procedure  that  may  have  pro¬ 
duced  good  stuff  from  stock  resulting  from  a  certain  digester 
cook  would  have  to  he  altered  materially  to  deal  with  the  next 
cook  produced  under  slightly  different  conditions. 

Furnishing  Lap  Stock  to  the  Beater:  The  heater  should  be 
filled  up  with  water  until  the  roll  begins  to  circulate  the  water. 


THE  BEATER  ROOM 


231 


Assuming  that  the  furnish  is  to  consist  of  sulphite  and  ground 
wood,  the  sulphite  should  be  furnished  first,  the  laps  being  care¬ 
fully  opened  before  being  placed  in  the  beater.  During  the 
furnishing  the  roll  should  be  away  from  the  bed-plate  Sufficiently 
far  to  prevent  it  from  jumping  as  the  laps  of  stock  go  through. 
After  the  sulphite  has  all  been  furnished,  the  ground  wood  is 
put  in.  The  roll  should  be  kept  up  off  the  bed-plate  until  the  laps 
are  thoroughly  disintegrated,  then  the  roll  can  be  lowered  to  the 
degree  decided  on  by  the  beater  engineer.  Size,  color  and  alum 
can  then  be  added  in  the  order  mentioned.  A  sufficient  interval 
of  time  should  be  allowed  to  elapse  between  the  furnishing  of 
each  of  these  ingredients  so  that  each  will  be  thoroughly  worked 
up  with  the  pulp  before  the  other  is  added. 

In  making  paper  from  kraft  and  sulphite  separate  beaters 
should  be  used,  as  if  it  is  attempted  to  beat  them  in  one  and 
the  same  engine,  the  sulphite  will  be  overbeaten  long  before 
the  kraft  is  properly  worked  up.  The  best  way  is  to  use  two 
beaters,  one  for  the  sulphite  and  one  for  the  kraft  and  to  mix  the 
stock  in  a  chest  after  the  beating  is  completed. 

In  making  a  paper  75  per  cent  sulphite  and  25  per  cent  kraft, 
for  instance,  six  beaters  could  be  used,  five  on  kraft  and  one  on 
sulphite.  The  sulphite  can  be  dumped  after  half  an  hour’s  beat¬ 
ing  whereas  the  five  beaters  working  on  kraft  will  be  kept  run¬ 
ning  six  hours  or  more. 

In  making  book  and  writing  papers,  the  beaters  must  con- 
constantly  be  stirred,  special  attention  being  paid  to  the  corners 
where,  in  spite  of  fillets,  stock  will  accumulate. 

The  treatment  the  stock  receives  in  the  beaters  depends  to 
some  extent  on  what  is  going  to  happen  to  it  next.  The  next 
operation — treatment  in  the  Jordan  Engine  or  some  other  type  of 
refiner — is  generally  co-related  with  the  treatment  in  the  beater, 
and  the  work  of  preparing  the  stock  for  the  paper  machine  divided 
between  them.  Before  treating  of  the  Jordan  Engine,  however, 
we  will  discuss  some  of  the  materials  which  are  ordinarily  added 
to  the  stock  in  the  beaters.  The  chief  of  these  are,  clay,  size, 
alum,  talc,  coloring  materials,  etc. 

Clay. 

Paper  made  of  fibre  alone  is  more  or  less  transparent,  the 
degree  of  transparency  depending  chiefly  on  the  thickness  of  the 
paper,  but  also  on  the  nature  of  the  fibrous  material  itself, 
some  kinds  of  fibre  being  more  dense  and  opaque  than  others. 

In  order  to  overcome  the  transparency  of  thin  papers  such 
as  newsprint  and  also  to  give  the  paper  other  desirable  quali¬ 
ties  (such  as  a  better  printing  surface  and  a  lessening  of  the 
friction  when  in  contact  with  the  type  on  the  printing  press), 
it  is  generally  advisable  to  load  such  papers  with  some  inert 
material. 


232 


MODERN  PULP  AND  PAPER  MAKING 


Such  inert  materials  used  for  loading  are  known  as  “fillers.” 
The  commonest  of  these  fillers  is  Kaolin  or  China  clay. 

This  substance  occurs  naturally,  being  a  hydrous  silicate  of 
aluminum,  formed  by  the  weathering  and  disintegration  of  cer¬ 
tain  kinds  of  rock.  It  occurs  throughout  the  world  but  until 
recently  clay  for  the  use  of  the  paper  industry  has  been  procured 
chiefly  from  Great  Britain.  Lately  deposits  of  clay  suitable  for 
paper  making  have  been  opened  up  in  the  United  States  and 
Canada.  The  majority  of  clay  deposits  throughout  the  world  are 
not  suitable  for  the  use  of  the  paper  industry  because  of  the 
presence  of  impurities. 

The  composition  of  clay  will  always  vary  ov/ing  to  the  pres¬ 
ence  of  impurities  but  a  good  average  sample  should  run  from 
47  to  50  per  cent  SiOa ;  34  to  40  per  cent  AI2O3 ;  12  to  15. 
cent  chemically  combined  water.  The  usual  chemical  impurities 
are  iron,  calcium  and  the  alkalies.  Clay  containing  more  than 
one  per  cent  iron  should  never  be  used  as  iron  will  impart  color 
to  the  paper.  For  making  good  white  paper,  clay  should  be 
perfectly  white  in  color,  very  fine  and  free  from  grit. 

The  following  table  taken  from  Griffin  and  Little  gives  an 
analysis  of  four  clays  (presumably  British),  suitable  for  the  use 
of  paper  makets : 


Analysis  by  Griffin  and  Little 


I 

II 

III 

IV 

Moisture,  loss  at  100°  C . 

0.30 

10.15 

7.09 

9.10 

Combined  water,  volatile  at  red  heat 

12.27 

10.77 

11.27 

12.79 

Silica  (Si02) . 

47  56 

42.72 

43-50 

41 . 16 

Alumina  (AijOa) . 

38.12 

33-44 

35-48 

35-84 

Sesquioxide  of  iron  (FezOs) . 

0.08 

1 .04 

trace. 

0.67 

Lime  (CaO) . 

0.39 

1 .61 

0.17 

0.42 

Magnesia  (MgO) . 

0.00 

0. 16 

0.41 

0.02 

Alkalis . 

1 .28 

0.  II 

2.08 

.... 

100.00 

100.00 

100.00 

100.00 

Specific  gravity  of  dry  substances. . . 
Grit  by  flotation  test  (per  cent) . 

2 . 8625 
0.65 

2.5585 

6.83 

2.5451 

0. 10 

On  page  233  is  the  analysis  of  a  clay  mined  in  Quebec, 
Canada,  which  is  being  used  with  satisfactory  results  by  Cana¬ 
dian  paper  makers  and  a  clay  from  the  Aiken  district  in  South 
Carolina  which  has  also  been  found  satisfactory. 

Whether  a  clay  is  suitable  for  paper  making,  or  not,  cannot, 
however,  be  decided  by  chemical  analysis,  although  all  clays 
considered  for  use  should  always  be  analyzed  to  prove  the  ab¬ 
sence  of  chemical  impurities  in  excessive  amounts.  The  physical 
properties  of  the  clay  are  equally  as  important  as  the  chemical 
properties.  These  physical  properties  are  the  result  of  the  geo- 


THE  BEATER  ROOM 


233 


Analysis  of  Clays  from  U.  S.  and  Canada 


St.  Remi  d ’Amherst 
Aiken,  S.C.  Quebec,  Canada 


Silica .  45  67  46  - 13 

Alumina . 37.86  39-45 

Iron  oxide .  1.48  0.72 

Lime . .  0.05  none 

Magnesia .  o.oi  none 

Alkalis . .  0.80  0.29 

Combined  water .  13.22  13.81 

Per  cent  grit .  1.88  not  estimated 


logical  history  of  the  clay.  A  detailed  discussion  of  this  matter 
would  belong  more  in  a  work  on  mineralogy  than  in  the  present 
volume.  However,  the  chief  point  is  the  presence  of  what  the 
chemist  calls  “colloids”  in  the  clay.  This  means  that  the  fine 
particles  of  clay  will  remain  in  suspension  almost  indefinitely 
when  the  clay  is  mixed  with  water.  It  is  the  presence  of  this 
colloid  structure  that  gives  the  clay  the  greasy,  slippery,  tenacious 
consistency  when  mixed  with  a  small  quantity  of  water,  which 
is  characteristic  of  all  good  clays.  Further  on  we  shall  give 
some  simple  tests  by  which  the  paper  maker  can  determine 
whether  a  clay  is  suitable  for  his  use  from  the  standpoint  of 
physical  properties. 

American  Clays  vs.  British  Clays:  There  does  not  seem  to 
be  any  good  reason  why  American  clays  should  not  be  more 
used  in  this  country  than  they  are.  However,  trade  tends  to  fol¬ 
low  beaten  paths,  and  even  during  the  war  when  trans-Atlantic 
shipment  was  uncertain  and  expensive,  large  tonnages  of  Britisn 
clay  were  imported. 

According  to  T.  Poole  Maynard,^  a  chemist  with  experience  in 
the  clay  industry,  American  clays  are  available  in  immense  ton¬ 
nages  of  superior  quality  to  any  now  imported  from  England. 

The  use  of  American  clays  is  gradually  increasing.  In  1915 
Georgia  and  South  Carolina  produced  92,000  tons  of  clay  suitable 
for  paper  making,  and  in  1916  125,000  tons.  In  1916  the  total 
tonnage  of  such  clays  produced  in  the  United  States  was  200,000 
and  in  the  same  year  more  than  250,000  tons  were  imported  from 
England.  The  production  of  clay  for  paper  making  in  the  United 
States  decreased  in  1917  and  1918  owing  to  lack  of  labor;  it 
is  now  again  on  the  increase. 

Preparation  of  Clay:  In  preparing  clay  for  the  market,  the 
crude  product  is  thoroughly  washed  with  water  and  the  gritty 
impurities  allowed  to  settle  in  large  tanks.  From  these  tanks 
the  water  is  decanted  off  before  the  fine  particles  of  clay  have 
had  time  to  settle.  The  clay  is  then  allowed  to  settle  in  tanks 

*  Paper  before  tbe  'Technical  Association  qf  the  fulp  and  Taper  Indii.stry,  1919, 


234  MODERN  PULP  AND  PAPER  MAKING 

from  which  the  clear  water  is  siphoned  off.  The  thick,  creamy 
white  sludge  containing  the  pure  clay  is  then  dewatered  in  filter 
presses  and  the  cakes  dried  and  prepared  for  shipment. 

Of  course,  the  strength  of  any  paper  is  weakened  by  putting 
in  a  filler  with  the  fibre  but  since  the  surface,  finish,  feel  and 
general  characteristics  of  the  papm-  are  improved  by  the  addi¬ 
tion  of  fillers,  it  is  generally  advisable  to  do  so.  However,  it 
requires  experience  and  good  judgment  to  determine  in  all  cases 
just  what  proportion  of  filler  should  be  used.^ 

Clay  is  usually  used  as  a  filler  in  newsprint  and  the  cheaper 
grades  of  writing  and  book  paper.  The  better  qualities  of  wiiting 
and  book  paper  are  usually  loaded  with  special  materials  such  as 
agalite,  calcium  sulphate,  pearl  hardening,  barium  sulphate,  etc. 

For  use  in  the  beaters,  the  clay  is  usually  niade  into  a  thin 
cream  with  water,  this  generally  being  done  in  a  small  tank 
fitted  with  an  agitator.  Some  paper  makers  mix  the  clay  with 
rosin  size  before  adding  it  to  the  beaters,  it  being  believed  that 
this  procedure  aids  in  the  retention  of  the  filler  by  the  fibres. 

A  good  clay  should  feel  smooth  and  soapy  between  the  teeth 
and  should  not  scratch  a  finely  polished  metal  surface.  ^  The 
best  test  for  clay  is  to  drop  a  few  lumps  of  the  dried  clay  into  a 
glass  of  water  and  without  stirring  observe  the  behavior  of  it. 
A  good  clay  will  emit  numerous  bubbles  with  a  slight  buzzing 
sound  and  as  the  water  penetrates,  will  gradually  break  down 
into  a.  fine  powder  which  rolls  off  from  the  surface  leaving  the 
lumps  until  finally  it  is  all  broken  down  into  a  powder. 

Upon  stirring  up  the  mixture  with  more  water,  pouring  off 
the  fine  milk,  adding  more  water,  stirring  and  pouring  off,  very 
few  particles  of  clay  will  be  left  in  the  glass. 

If  instead  of  forming  a  fine  powder  which  rolls  off  the  surface 
of  the  lumps,  the  lumps  crack  into  small  pieces  as  the  water 
penetrates  them  and  these  small  pieces  crack  again  ^  and  so  on, 
the  clay  is  not  satisfactory  and  will  give  rise  to  “clay  spots 
in  the  paper. 

Before  adding  clay  to  the  paper  it  should  always  be  screened 
through  a  wire  cloth  to  remove  any  impurities  that  may  have 
been  left  in  the  clay  in  manufacture  or  that  may  have  got  into 
it  during  shipment  and  storage. 

The  thinner  the  clay  liquid  is  and  the  longer  it  can  be  stirred, 
the  better  it  will  be.  There  being  fewer  lumps  to  screen  out, 
the  screening  will  be  more  rapid  and  easy,  a  finer  wire  cloth 
can  be  used  for  the  screening,  and  it  will  flow  better  through 
the  pipes.  A  thick  mixture  of  clay  and  water  of  this  kind  is 
called  “slip.” 

A  convenient  strength  of  slip  for  furnishing  to  a  beater  is 
made  by  dumping  a  cask  of  about  2400  pounds  of  clay  into  a 
tank  holding  about  2400  gallons,  partly  filled  with  water,  stirring 
and  adding  water  until  the  tank  is  filled.  This  gives  a  slip 
each  gallon  of  which  contains  one  pound  of  clay.  By  this  means, 


THE  BEATER  ROOM 


235 

it  is  very  easy  to  gauge  the  amount  of  clay  being  furnished  to 
the  beaters. 

A  good  arrangement  is  to  make  up  the  “slip”  in  a  small  tank 
or  box  above  the  beaters.  Hot  water  slacks  clay  more  readily 
than  cold  water  and  it  is  of  considerable  advantage  to  warm 
the  water  especially  in  cold  weather.  When  clay  is  slacked  in  the 
above  manner,  in  small  tanks  or  boxes  above  the  beaters,  and 
when  any  size  is  being  used  in  the  paper,  it  is  a  good  plan  to  use 
hot  water  for  slacking  the  clay  and  to  dissolve  the  size  at  the 
same  time.  I 

The  alkali  of  the  size  causes  the  clay  to  slack  more  readily  to 
a  fine  slip.  Alum,  however,  should  never  be  added  when  slack¬ 
ing  the  clay  as  it  makes  the  clay  floculate  together  giving  a  slip 
of  course  consistency.  Alum  should,  therefore,  always  be  furn¬ 
ished  separately  and  not  mixed  with  the  clay  and  water.  More¬ 
over,  alum  acts  injuriously  upon  iron  pipes,  valves  and  agitators. 

In  mills  where  large  quantities  of  clay  are  made  into  slip 
in  large  tanks  and  then  pumped  to  the  beaters,  it  is  not  advisable 
to  mix  the  size  with  it,  as  it  gives  rise  to  much  foam  during 
the  stirring  and  screening  and  when  water  is  run  into  the  tank 
for  the  next  batch. 

At  frequent  intervals  samples  of  clay  used  should  be  sent  to 
the  laboratory,  or  to  an  analytical  office,  for  chemical  analysis 
and  for  physical  and  microscopical  tests.  Only  in  this  manner 
can  the  mill  be  sure  that  the  best  quality  of  clay  is  being  used 
and  that  too  high  a  price  is  not  being  paid  for  the  grade  specified. 

Soda  pulp  as  a  rule  requires  less  filler  than  sulphite  pulp 
because  it  is  naturally  bulkier  and  less  transparent.  However, 
with  no  kind  of  stock  should  excessive  quantities  of  clay  be 
used  as  it  will  dust  off  on  the  printing  presses,  contaminating 
the  ink  and  giving  poor  results.  The  excessive  use  of  clay  is 
also  a  needless  expense  as  the  fibre  will  only  retain  a  certain 
amount  and  a  great  deal  of  clay  will  be  wasted  in  the  white 
water  if  too  much  is  added.  The  proper  amount  to  use  for 
newsprint  is  generally  about  5  per  cent.  The  amount  to  be 
used  with  other  grades  of  paper  depends  entirely  on  the  effect 
it  is  desired  to  produce  and  must  always  be  a  matter  of  individual 
judgment  and  experience. 

In  making  newsprint,  when  a  mill  is  well  ec[uipped  with 
save-alls  and  facilities  for  utilizing  the  white  water,  it  is  gen¬ 
ially  cheaper  to  use  clay  liberally  and  ground  wood  more  spar¬ 
ingly.  The  exact  balance  betwen  clay  and  ground  wood  in  news¬ 
print  must,  however,  be  worked  out  as  a  matter  of  practical  ex¬ 
perience.  In  ordinary  news  print  about  one-half  of  the  clay 
furnished  is  retained,  but  this  varies  considerably  according  to 
local  conditions.  The  amount  of  size  used  has  a  direct  effect 
on  the  retention  of  the  clay,  but  ordinarily  in  making  the  news¬ 
print,  no  size  is  used  at  all  except  on  special  orders.  Alum  also 
has  an  effect  on  the  retention  of  the  clay  but  it  is  not  desirable 


236  MODERN  PULP  AND  PAPER  MAKING 

to  use  too  much  alum  because  it  exerts  a  hardening  effect  on 
the  paper.  Moreover,  it  is  not  economical  tO'  use  2  cents’  worth 
of  alum  in  order  to  save  i  cent’s  worth  of  clay. 

The  only  source  of  loss  in  the  use  of  clay  is  in  the  white 
water  which  is  allowed  to  run  to  waste,  and  if  it  were  possible 
to  re-use  every  gallon  of  white  water  and  have  none  go  to  waste, 
there  would  naturally  be  no  loss  of  clay  or  of  fibre.  Many  effi¬ 
cient  devices  are  on  the  market  for  recovering  the  clay  and  fibre 
from  white  water.  See  page  353. 

Some  paper  makers  object  to  the  re-use  of  white  water, 
liking  to  use  plenty  of  fresh  water  because  of  a  fear  that  white 
water  causes  slime  to  accumulate.  Some  paper  makers  go  so 
far  as  to  use  fresh  water  exclusively,  permitting  all  the  white 
water  to  go  to  waste  after  passing  through  a  save-all  for  removing 
the  fibre.  This  is  rarely  necessary  except  in  a  few  mills  where 
exceptionally  fine  grades  of  writing  paper,  etc.,  are  being 
made. 

It  is  our  opinion  that  the  prejudice  against  the  use  of  white 
water  is  largely  unwarranted  and  instead  of  avoiding  its  use 
we  believe  that  as  much  as  possible  should  be  used.  There  is 
an  opportunity  at  almost  every  mill  to  effect  considerable  saving 
of  clay  and  fibre  by  careful  attention  to  the  disposal  of  the  white 
water. 

The  following  is  a  table  based  on  tests  at  certain  mills  show¬ 
ing  the  retention  of  clay  in  hangings  and  news-print : 


Kind  of  Paper 

%  of  clay 
furnished 

%  found 

%  retention 

Hanging . 

...  13.00 

7.81 

60.08 

Hanging . 

...  13.00 

8.10 

62.31 

News . 

...  13.00 

4-85 

37-31 

News . 

...  13.00 

4.81 

37.00 

News . 

...  13.00 

4-53 

34-85 

News . 

...  13.00 

452 

34-77 

News . 

. ..  13.00 

4.41 

33-92 

The  hanging  paper  shows  a  fairly  good  retention  but  the 
retention  in  the  case  of  tbe  news  is  quite  poor.  We  believe  that 
a  furnish  of  about  one-half  as  much  clay  would  give  equally 
good  results  and  would  show  a  much  larger  percentage  of 
retention. 

In  a  certain  mill  the  writer  knows  of  200  pounds  of  clay 
are  used  to  a  beater  each  round  and  out  of  each  round  they  make 
2150  pounds  of  pap6r.  Consequently,  9.2  per  cent  is  furnished, 
the  per  cent  of  clay  found  in  the  paper  was  7.9,  consequently 
the  percentage  of  retention  is  85.87  per  cent.  The  cause  of 
such  a  high  retention  was  because  this  mill  was  very  careful 
in  the  use  of  white  water  and  in  preventing  clay  going  to  waste. 
They  also  used  quite  a  large  amount  of  alum  and  the  paper 
.was  very  heavy. 


THE  BEATER  ROOM 


237 


Testing  of  Clay. 


Moisture:  Weigh  from  one  to  two  grams  of  the  clay  in  a  clip 
of  a  watch  glass  and  dry  m  oven  at  120°  C.  until  the  weight  is  con- 
stant.  The  weight  lost  equals  the  moisture  present  in  the  clay. 

Combined  ll  ater:  Weigh  from  one  to  two  grams  of  the 
clay  m  a  crucible  and  heat  oyer  the  highest  heat  in  a  blast  lamp 
for  about  15  minutes  or  until  the  weight  is  constant.  The  loss 
in  weight  equals  the  per  cent  of  moisture  equals  the  amount 
of  combined  water. 


Total  Sihca:  Weigh  one  gram  of  clay  in  a  platinum  foil  and 
transfer  to  a  casserole,  add  20  cc.  of  sulphuric  acid  (i  to  i) 
10  cc  of  concentrated  hydrochloric  acid  and  5  cc.  of  concen¬ 
trated  nitric  acid.  Cover  with  a  watch  glass  and  boil  the  mix¬ 
ture  rapidly  m  gas  plate  until  fumes  of  sulphuric  anhydride  are 
given  off.  Continue  to  heat  just  below  the  boiling  point  of 
sulphuric  acid  for  two  hours  and  add  55  cc.  of  water.  Brino- 
to  a  boil  and  then  heat  in  the  steam  plate  for  30  minutes.  Filter 
off  the  separated  silica  and  collect  the  filtrate  in  a  200  cc. •gradu¬ 
ated  flask.  Ignite  the  precipitate  while  still  wet  in  a  platinum 
^ucible,  completing  the  ignition  by  blasting  for  20  minutes 
Cool  and  weigh.  Add  a  few  drops  of  dilute  sulphuric  acid  and  a 
sufficient  quantity  of  hydrochloric  acid.  Heat  over  a  very  low 
flarne  until  the  acids  are  volatilized  and  then  ignite  at  full  heat 
of  burner.  Cool  and  weigh.  The  loss  in  weight  represents  the 
total  silica  present  in  the  clay.  The  residue  rarely  exceeds  five 
milligrams  and  is,  therefore,  added  directly  to  the  weight  of  the 
iron  and  alumina  precipitate. 

Tree  Silica:  Weigh  one  gram  of  the  clay  in  a  casserole  and 
then  treat  m  same  manner  as  in  the  total  silica.  Filter  off 
the  sihca  and  transfer  paper  and  precipitate  to  a  platinum  dish. 
Ignite  gently  on  a  Brosson  flame  until  the  filter  paper  is  entirely 
consumed,  cool  and  add  50  cc.  of  a  hot  is  per  cent  solution 
of  potassium  hydroxide.  Boil  for  6  minutes  and  filter  off  the  free 
silica,  which  remains  undissolved,  washing  with  hot  water  slightly 
acidulate  with  hydrochloric  acid  and  ignite,  cool  and  weigh,  treat 
with  dilute  sulphuric  acid  and  hydrochloric  acid  and  heat  over 
a  low  flame  until  all  acid  is  volatilized.  Ignite,  cool  and  weigh, 
f  he  loss  in  weight  represents  the  free  silica  in  the  clay. 

Iron  and  Alumina:  If  the  residue  from  the  hydrofloric  acid 
treatment  of  the  total  silica  which  is  so  small  as  to  render  fusion 
with  acid  potassium  sulphate  unnecessary,  then  cool  the  filtrate 
from  the  total  silica,  dilute  to  mark  and  shake  well.  Draw  with 

solution,  transfer  to  a  200  cc.  beater  and 
add  about  5  cc.  concentrated  hydrochloric  acid  and  a  few  drops 
0  l^flric  acid.  Heat  to  a  boiling  and  add  dilute  ammonia  until 
a  s  ight  excess  is  present,  continue  to  boil  until  the  odor  of  am- 
monia  is  only  slightly  perceptible.  After  standing  a  short  time, 
Alter  off  the  precipitate  by  means  of  suction.  Wash  with  hot 


238  MODERN  PULP  AND  PAPER  MAKING 

water,  dry  the  precipitate  and  ignite  in  platinum  crucible.  Finish 
the  ignition  by  blasting  for  about  30  minutes,  cool  and  weigh  as 

AI2O3  plus  FegOs-  1  •  .1 

Iron:  Evaporate  the  filtrate  from  the  silica,  used  m  the  de¬ 
termination  of  free  silica,  to  about  100  cc.  reduce  tjie  iron  m  the 
usual  manner  by  means  of  a  Jones  Reducer,  and  filtrate  with 
standard  potassium  permanganate.  Express  result 

Alumina:  Subtract  the  percentage  of  iron  from  that  of  the 
iron  and  aluminum  combined.  The  result  represents  the  per¬ 
centage  of  ALOo.  ,  ,  1  -I- 

Calcium  Oxide:  In  100  cc.  of  the  filtrate  from  the  total  silica, 

precipitate  the  iron  acid  and  alumina  with  ammonia,  filter  and 
wash  well.  Heat  the  filtrate  to  boiling  and  precipitate  the  lime  as 
calcium  oxalite  by  the  addition  of  a  hot  solution  of  ammonia 
oxalate.  Filter  off  the  precipitate,  ignite  to  constant  wt.  cool  and 

Oxide:  Add  a  slight  excess  of  hydrochloric  acid 
to  the  calcium  oxalate  filtrate  evaporate  to  about  100  cc.  Ad( 
an  excess  of  sodium  ammonium  phosphate,  stw  until  dissolved 
and  add  concentrated  ammonia  drop  by  drop  with  constant  stirr¬ 
ing  until  a  considerable  excess  is  present.  Cool  m  ice  water  toi 
about  two  hours,  filter,  and  wash  the  precipitate  with  ammonia 
wash  water.  Place  the  moist  precipitate  in  a  platinum  crucible 
and  carefully  smoke  off  the  filter  paper.  Finish  the  ign^^on  over 
a  hot  blast,  cool  and  weigh  as  MgaPoO^.  Calculate  to  MgO.  _ 
Notes  and  Precautions:  In  the  majority  of  cases  the  acid, 
treatment  of  the  clay  gives  as  complete  a  decomposition  as  the 
sodium  carbonate  fusion,  and  the  residue  left  from  the  hydroflonc 
acid  treatment  of  the  silica,  should  not  amount  to  more  than  five 
milligrams.  In  case  this  residue  is  excessively  large  it  then 
becomes  necessary  to  fuse  the  residue  with  a  small  amount  of 
acid  potassium  sulphate.  This  fusion  is  dissolved  in  hot  water 
and  solution  then  added  to  the  200  cc.  flask  containing  the  filtrate 
from  the  total  silica,  which  is  then  diluted  to  the  mark,  and  the 
50  cc.  portion  taken  for  the  determination  of  iron  and  alumina. 

The  determination  of  free  silica  is  not  an  accurate  one,  when 
there  is  a  large  portion  of  the  clay  remaining  undecomposed  by 
the  acid  treatment,  for  the  reason  that  no  free  silica  can  be 
obtained  in  the  total  silica  derived  from  an  alkali  fusion. 


EXAMPLE  OF  TESTS  AND  CALCULATIONS  REG.VKOINCi  RETENTION  OF 


CLAY 


Clay  used,  gave  moisture  and  combined  water . 

Dry  clay .  ^5-05% 

100.00% 


THE  BEATER  ROOM 


239 


Ash  (Clay)  in  4  Samples: 

(1)  2.700%  ash 

(2)  3-123%  ash 

(3)  3  366%  ash 

(4)  3.420%  ash 


which  averaged  3- 152%  ash 

These  results  are  figured  on  the  basis  of  the  paper  contain¬ 
ing  10  per  cent  moisture.  Average  percentage  of  ash  in  paper 
containing  no  filler  was  found  to  be  0.46  per  cent.  Hence  per¬ 


centage  of  dry  clay  in  paper  was  3.152  —  0.46  or  2.692  per 
cent.  Calculating  the  dry  clay  to  original  clay  used  2.692  -4- 

85-05  =  3-i6. 

Total  production  of  paper  was .  5 >980,430  lbs. 

3. 16%  of  which  is  clay  188,981  lbs. 

Returned  waste  was .  29,740  lbs. 


3.16%  of  which  is  clay  939  lbs.  5)950,690  lbs. 


Hence  the  clay  in  the  paper  made  was  188,339 
Actual  clay  used  in  one  particular  month  was 
365,974  lbs. 

The  percentage  of  retention  was  51.46% 


Tbe  following  table 

shows  the  percentage  of  clay  used,  the 

percentage  found,  and 

the  percentage 

retained  in  a  number  of 

different  operations. 

Per  cent 

Per  cent 

Per  cent 

clay  used 

clay  found 

clay  retained 

12.57 

9. II 

72.5 

12.00 

6.05 

50-4 

11.72 

7.66 

654 

11.40 

7.24 

634 

10.02 

7.06 

70.3 

9.29 

458 

49  I 

7  38 

4-55 

61 . 8 

6.03 

3-23 

53-6 

5  99 

2.91 

48.7 

5-57 

2.34 

42.2 

4.87 

2.63 

54-1 

4-43 

2.26 

51-2 

2.96 

1.56 

52-4 

Retention  of  Clay. 

In  order  to  determine  the  above  values  the  following  method 


was  used : 

1st.  The  weight  of  clay  at  each  mill  used  for  each  month 
was  reported  and  a  sample  sent  to  testing  department. 

2nd.  The  total  w'eight  of  paper  made  each  month  and  a 
sample  of  such  paper  taken  every  six  hours  was  sent  to  the 
testing  department. 

3rd.  The  total  weight  of  returned  waste  was  reported. 

4th.  The  total  weight  of  paper  made  without  clay,  and  a 
sample  was  sent  to  the  testing  department. 

From  this  data  the  per  cent  retention  was  calculated  as  de¬ 
scribed  above. 


240 


MODERN  PULP  AND  PAPER  MAKING 


Tests  on  English  Clay 

First  Test 

3%  of  (finished  product)  of  clay  used. 

Ground  wood  used^(wet  weight  •) . .  83,976  lbs.  (dry  weight.) .  .  26,872  lbs. 
Sulphite  used  (wet  weight.) . 19,018  lbs.  (dry  weight.) .  .  6,846  lbs. 


33,718  lbs.  dry 

Clay  used  2.4%  of  i  equals  812  (2  }^%  of  total  wt.  of  stock) 

Alum .  290  lbs. 

Size .  174  lbs. 

Total .  34,994  dry  weight 

Paper  made .  27,515  lbs.  33, 7^8 

Waste  and  shav-  1,276 

ings .  4,147  lbs.  - 

Sweepings  (wet) . .  95  lbs.  34,994  equals  110%  of 

- - -  total  stock 

Total .  31,757  lbs. 

Second  Test 

6%  (finished  product)  clay  used. 

Ground  wood  (wet  weight.) .  86,031  lbs.  32%  dry.  27,529  lbs. 

Sulphite  (wet  weight.) .  22,148  lbs.  36%  dry.  7,973  lbs. 


Clay  used  5.2%  of  i 

Alum . 

Size . 


35,502  lbs. 

1,881  lbs.  (5%  total  weight) 

320  lbs. 

198 


Total .  2,899 


37,901  lbs. 

Paper  made .  31,365  lbs. 

Waste .  4,126  lbs. 

Sweepings .  273  lbs. 


35,764  lbs. 

These  tests  show  a  shrinkage  of  about  10  per  cent.  The 
per  cent  of  clay  in  each  case  is  figured  on  2  different  bases. 

1st  on  the  basis  of  total  ground  wood  and  sulphite  used. 

2nd  on  the  basis  of  all  the  ingredients  used,  giving  the  clay 
added. 

Presumably  the  loss  in  weight  is  due  to  alum  and  size. 

This  report  is  given  to  determine  the  retention. 

To  get  the  retention,  we  add  to  the  ground  wood  and  sulphite, 
the  amount  of  clay  used,  and  then  divide  by  the  amount  of  clay 
which  gives  the  percentage  of  clay  used. 

This  ignores  alum  and  sizings.  After  obtaining  the  per  cent 
of  clay  used  as  above,  we  divided  the  percentage  of  actual 
clay  returned  by  this  and  thus  obtained  the  percentage  of  re¬ 
tention. 

The  retentions  in  the  two  cases  were  62.44  and  63.00  per  cent. 
Other  Loading  Materials. 

Talc:  A  naturally  occurring  mineral  found  in  almost  every 
state  and  in  Canada.  Chemically  it  is  a  hydrous  magnesium 


THE  BEATER  ROOM 


241 


silicate.  Its  most  conspicuous  property  is  its  soft,  greasy  feel. 
Its  use  is  not  confined  to  paper  making,  large  quantities  being 
used  in  the  manufacture  of  talcum  powder,  rubber  goods,  etc. 
After  being  mined,  the  talc  is  pulverized  so  that  it  will  pass 
through  a  200-mesh  screen  and  then  bolted  through  fine  cloth  or 
graded  with  an  air  separator.  Talc  is  not  so  much  used  as 
clay  in  paper  but  is  necessary  for  some  varieties  of  surface  and 
is  much  used  in  paper  coating  mills. 

Agalite:  This  is  a  filler  chemically  the  same  as  ordinary  talc, 
but  of  somewhat  differept  physical  structure,  being  prepared 
from  a  variety  of  talc  that  is  more  like  asbestos.  In  fact,  min- 
eralogically  the  talcs  and  the  various  sorts  of  asbestos  are  very 
closely  related.  On  account  of  its  fibrous  structure,  agalite  is  a 
very  useful  loading  material.  Just  like  talc,  however,  it  makes 
the  paper  loaded  with  it  very  greasy. 

The  terms  agalite  and  talc  are  used  very  loosely  and  inter¬ 
changeably  by  practical  paper  makers.  Asbestine,  French  chalk, 
mineral  pulp,  etc.,  are  all  other  names  for  the  same  thing. 

Pearl  Hardening:  This  is  calcium  sulphate  (sulphate  of 
lime,  artificial  gypsum,  etc.),  prepared  artificially.  It  is  much 
used  as  a  filler  in  the  better  grades  of  paper.  When  properly 
prepared  it  is  white  and  free  from  grit.  The  commercial  article 
contains  considerable  mechanically  contained  water  in  addition 
to  the  combined  water. 

Crozvn  Eiller:  This  is  another  name  for  pearl  hardening. 

Ground  Gypsimi:  Sometimes  known  as  “terra  alba.”  Chem¬ 
ically  this  is  the  same  as  pearl  hardening,  but  it  is  made  by 
grinding  and  bolting  naturally  occurring  gypsum.  It  is  not  used 
so  much  as  pearl  hardening. 

Satin  White:  This  is  an  artificially  prepared  filler  contain¬ 
ing  calcium  sulphate  and  alumina.  It  is  usually  sold  in  casks 
or  drums  in  the  form  of  a  paste.  This  filler  gives  a  high  per¬ 
centage  of  retention  owing  to  the  alum  it  contains. 

Size. 

Size  is  any  substance  which  is  added  to  a  porous  or  absorbent 
surface  to  render  it  less  so.  Sizing  is  by  no  means  confined 
to  the  paper  industry.  A  plastered  wall  is  sized  by  brushing  it 
over  with  weak  glue  or  shellac,  etc. 

Paper  needs  to  be  sized  to  prevent  the  spreading  of  ink,  to 
give  it  a  good  surface,  to  impart  the  proper  degree  of  stiffness 
and  rattle,  etc. 

The  principle  of  sizing  is  to  add  some  material  that  will 
fill  up  the  pores  between  the  fibres  and  the  filler,  thus  preventing 
ink  or  moisture  spreading  by  capillary  action,  just  like  oil  spreads 
upwards  in  a  wick. 

Naturally,  various  degrees  of  sizing  are  required.  Blotting 
paper  and  filter  paper  are  not  sized  at  all,  as  it  is  intended 
that  they  should  soak  up  liquids.  Newsprint  is  sized  very  little — 


242 


MODERN  PULE  AND  PAPER  MAKING 


sometimes  not  at  all — because  the  heavy  viscid  printing  ink  does 
not  tend  to  spread  much.  Good  writing  papers  require  a  lot 
of  size  because  they  are  written  on  with  fluid  inks. 

Several  different  materials  are  used  for  sizing.  Rosin  size, 
however,  is  at  present  by  far  the  most  usual. 

Animal  Rising:  This  was  introduced  in  the  days  when  paper 
was  still  made  by  hand.  It  is  still  used  in  England  and  in  certain 
mills  in  America  making  fine  writing  and  drawing  papers.  This 
size  is  really  a  solution  of  gelatine,  prepared  by  soaking  hides  in 
water.  The  size  was  applied  to  the  paper  after  the  sheets  were 
made,  by  dipping  the  sheets  in  a  vat  of  the  size. 

In  America  today  so-called  animal  sizing  is  done  with  solu¬ 
tions  of  commercial  glue  and  gelatine  and  the  paper  is  led  from 
the  machine  through  a  trough  or  vat  containing  the  size.  These 
machines  are  usually  called  size  presses  and  are  placed  in  the 
dryer  part  of  the  papermachine,  the  dryers  being  separated  into 
two  nests. 

The  drying  of  animal  sized  paper  is  an  operation  requiring 
great  care.  It  must  be  carried  out  slowly  and  at  a  low  tempera¬ 
ture.  Frequently  such  paper  is  “loft  dried,”  i.  e.,  the  sheets  are 
suspended  on  poles  in  a  warm  dry  loft.  This  treatment  brings 
out  very  fine  qualities  in  the  paper.  When  loft  drying  is  not 
resorted  to,  sometimes  special  forms  of  mechanical  dryers  are 
used  in  which  the  paper  is  festooned  in  a  blast  of  warm  air,  as 
in  a  coating  mill. 

Engine  Sizing:  This  is  the  term  applied  to  the  addition  of 
size  to  the  beater  where  the  stock  is  being  prepared  for  the 
paper  machine.  This  is  the  usual  method  of  sizing.  The  size 
most  usually  added  is  rosin  size. 

Rosin  Size:  Rosin  is  a  resin  obtained  in  the  manufacture  of 
turpentine  spirits  from  crude  turpentine,  which  is  a  natural 
product  obtained  from  pine  trees.  There  are  numerous  grades 
of  rosin,  these  grades  being  determined  by  the  color.  The  grades 
are  distinguished  by  letters  of  the  alphabet.  Rosin  is  graded 
B,  C,  D,  E,  F,  G,  H,  I,  K,  L,  M,  N,  W-G  (window  glass),  W-W 
(water-white).  B  is  the  darkest  and  W-W  the  lightest  grade. 
Ordinarily  the  first  three  grades  B,  C  and  D,  are  not  separated. 
The  grades  E,  F  and  G  are  the  ones  usually  employed  for  mak¬ 
ing  size  in  the  paper  industry.  The  other  grades  are  used  in 
other  lines  of  manufacture.  Rosin  is  sold  in  rather  peculiar 
units  of  280  lbs.  This  is  derived  from  the  English  gross  ton. 
However,  the  280-lb.  bbl.  includes  the  weight  of  the  container. 

Provided  that  the  darker  color  is  not  harmful,  it  is-  better 
to  use  E  or  even  D  rosin  than  the  lighter  F  and  G  as  the  sizing 
value  is  higher.  However,  D  and  G  are  the  limits  and  should 
not  be  exceeded  in  either  direction. 

Rosin  is  a  weak  acid  and  will  combine  with  an  alkali  to  form 
a  chemical  compound,  known  as  a  resinate.  In  making  size 
the  rosin  is  made  to  combine  with  sodium  carbonate  or  soda 


243 


THE  BEATER  ROOM 

ash.  Usually  58  per  cent  soda  ash  is  used.  A  table  telling  how 
soda  ash  is  graded  will  be  found  at  the  back  of  the  book. 
Rosin  and  soda  ash  do  not  react  until  heated.  When  mix^ 
and  heated  they  combine,  carbon  dioxide  gas  being  given  oft, 

which  gives  rise  to  foaming.  ,  1  1 

The  usual  method  of  making  the  size  is  to  dissolve  the  soda 
ash  in  water  in  a  kettle  heated  by  a  steam  coil  or  a  jacket. 
Sometimes  the  kettle  is  heated  by  direct  steam,  but  this  is  not 
good  as  it  is  necessary  to  make  allowance  for  the  dilution  from 
the  steam  in  weighing  out  the  materials  for  the  size.  When  the 
soda  liquor  is  ready,  the  finely  powdered  rosin  is  stirred  m  and 
the  whole  boiled  for  some  time,  after  which  it  is  diluted  with 

\v3.tcr 

The  proportion  of  soda  and  rosin  used  varies.  The  maxnnum 
amount  of  free  rosin  can  be  obtained  by  using  9  pounds  o^r 
soda  ash  and  100  pounds  of  rosin.  Such  size  is  rarely  used. 
From  20  to  40  pounds  of  soda  ash  per  100  pounds  of  rosin  is 
quite  usual.  The  writer  prefers  15  to  18  pounds  soda  100 
rosin.  The  soda  and  the  rosin  never  completely  combine,  i  hat 
is,  there  is  always  free  rosin  and  free  soda  in  the  size,  even  1 
just  the  right  quantity  of  soda  for  the  rosin  is  added.  The  amount 
of  free  soda  and  rosin  decreases  the  longer  the  size  is  boiled 
No  rule  can  be  given  for  the  percentage  of  free  or  of  combined 
rosin  that  a  size  should  contain.  It  depends  on  the  condition 
under  which  a  size  is  to  be  used,  the  nature  of  the  stock,  the 
water,  etc.  A  size  that  will  work  well  in  one  mill  may  be  use¬ 
less  for  another.  ,  ,•  1  1  j  ,.1 

After  cooking  until  the  lumps  of  rosin  are  dissolved  and  the 

batch  is  of  a  clear  dark  color,  when  the  steam  is  turned  off 
and  the  foaming  subsided,  a  test  is  made  as  follows . 

Take  a  pint  dipper,  of  hot  size  and  add  in  a  pail  a  quart 
of  hot  water  and  stir  until  well  mixed;  now  add  cold  water 
till  the  pail  is  nearly  filled  and  stir  again.  The  resulting  liquid 
should  have  a  white  or  yellow  color  and  dissolve  to  a  thin  milk 
free  from  lumps,  grains  or  sticky  pieces  of  rosin. 

If  it  does  not  readily  mix  with  water  and  dissolve  to  a 
mdk,  but  forms  grains  like  corn  meal,  it  must  be  again  cooked, 
but  the  cooking  must  again  be  stopped  when  the  test  shows  it 
to  be  done  as  further  cooking  injures  the  size. 

After  it  has  stood  for  a  day  or  two  a  black  liquor  separates 
which  is  brine  and  soda  ash.  This  should  be  removed  as  it 
causes  foaming  on  the  screens,  etc.,  and  the  running  off  of  the 
black  matter  is  of  a  great  advantage.  By  longer  standing  and 
occasional  poking  with  a  stick  more  liquor  can  be  made  to 
separate  from  it  and  more  should  be  worked  off. 

Notes  on  Making  Size. 

I — Caustic  soda  is  not  so  good  as  soda  ash  and  should 
not  be  used. 


244 


MODERN  PULP  AND  PAPER  MAKING 


2 —  Lime  is  harmful  rather  than  good. 

3 —  Brine  improves  size  by  washing  out  the  excess  of  soda. 

4 —  Ageing  size  is  good  for  it  separates  more  black  liquor 
from  it  and  ageing  can  be  hastened  by  using  fresh  brine. 

5 —  Thick  size  should  never  be  furnished  to  an  engine.  Thin 
size  is  made  by  dissolving  one  gallon  thick  size  in  four  gallons 
water. 

6—  — Heating  size  or  the  stock  in  the  beater  is  detrimental  to 
good  sizing  results  and  causes  foaming. 

7 —  Kerosene  is  bad  for  size  and  when  used  for  keeping  down 
foam  should  be  used  very  carefully. 

Process  Where  Direct  Steam  is  Used. 

The  equipment  consists  of  an  iron  tank  heated  by  direct 
steam  blown  into  it.  In  such  a  case  there  is  water  formed  by 
the  condensation  during  the  cooking  and  care  ‘must  be  taken 
to  use  at  first  as  little  water  as  possible,  for  the  reason  that  the 
weaker  the  solution  of  soda  ash  the  longer  it  takes  to  cook  the 
size.  Therefore,  only  a  sufficient  quantity  of  water  is  run  into 
the  tank  to  just  dissolve  the  soda  ash  used. 

Soda  ash  {must  he  dissolved:  The  water  is  first  heated  by 
steam  by  means  of  a  steam  pipe  until  the  soda  is  completely  dis¬ 
solved  and  no  undissolved  lump  should  be  left. 

Rosin  should  be  crushed  fine:  Rosin  is  next  shovelled  in, 
the  finer  it  is  crushed  the  quicker  the  cooking  is  completed.  The 
cooking  is  continued  as  rapidly  as  possible  without  it  running 
over  the  tank. 

To  prevent  boiling  water:  It  is  a  good  plan  to  have  a  sprin¬ 
kling  can  with  cold  water  to  stop  the  foaming  and  boiling  water. 
After  boiling  until  all  the  lumps  are  dissolved,  try  the  Solubility 
Test. 

Melted  Rosin  Process. 

The  following  method  of  making  size  has  proved  very  suc¬ 
cessful.  The  rosin  is  melted  over  night  in  a  steam  jacketed 
kettle.  A  strong  solution  of  soda  ash  is  made  up  and  then  added 
to  the  rosin  a  little  at  a  time.  At  first  the  action  is  very  violent, 
but  it  soon  moderates.  After  all  the  soda  is  added  the  size 
requires  very  little  boiling  to  be  done. 

When  the  rosin  size  is  dissolved  in  water  the  free  and  un¬ 
combined  rosin  does  not  go  into  solution  but  forms  a  sort  of 
emulsion  in  the  water,  this  giving  the  whole  a  milky  appearance. 
This  uncombined  rosin  attaches  itself  to  the  fibres  of  the  paper. 

However,  when  making  high  rosin  size  great  care  must  be 
exercised  to  have  it  exactly  right,  or  sticky,  tarry  masses  of 
rosin  will  separate  out  that  will  clog  tanks,  pipes  and  pumps, 
make  size  spots  in  the  paper,  adhere  to  felts  and  wires,  and 
cause  all  kinds  of  trouble.  Many  of  the  ready  made  sizes  are 


THE  BEATER  ROOM  245 

of  this  free  rosin  variety,  but  they  are  usually  made  with  care 
so  that  the  rosin  stays  in  solution. 

Ready  Made  vs.  Mill  Made  Size. 

Ready  made  size  is  undoubtedly  more  convenient  than  mak¬ 
ing  size  at  the  mill,  but  it  is  much  more  expensive  and  in  spite 
of  all  the  mystery  surrounding  the  subject,  any  practical  paper 
maker  should  be  able  to  learn  to  make  size  suitable  for  his  par¬ 
ticular  class  of  paper  after  a  little  experimenting. 

Various  Kinds  of  Rosin  Size. 

The  following  are  descriptions  of  some  of  the  kinds  of  size 
the  paper  maker  will  find,  or  will  be  given  recipes  for  making, 
in  many  mills : 

Highest  Free  Rosin  Size:  An  example  of  this  is  one  of 
the  ready  made  sizes  which  contains  so  much  rosin  that,  in 
order  to  get  it  into  solution  properly,  50  gallons  of  water  must 
be  used  to  dissolve  i  gallon  of  the  size.  One  third  of  the  50 
gallons  is  boiling  hot  and  the  hot  size  is  sprayed  into  this  water 
by  means  of  a  steam  injector.  The  other  2/3  of  the  water  is 
run  in  cold.  If  care  is  not  exercised  the  result  is  a  sticky,  un¬ 
manageable  mass.  There  is  no  doubt  that  such  size  gives  good 
results  and  is  economical  of  alum,  but  it  is  troublesome  and  in  the 
long  run  the  economy  is  doubtful. 

Second-Highest  Free  Rosin:  There  is  another  group  of  sizes 
on  the  market  containing  less  free  rosin  and  capable  of  being 
dissolved  without  the  need  of  special  appliances,  but  still  re¬ 
quiring  great  volumes  of  water  for  solution  and  being  very 
troublesome  to  handle. 

Most  Popular  Size:  The  most  generally  popular  size  is  that 
which  contains  a  large  amount  of  free  rosin,  but  not  so  much  but 
what  the  size  will  dissolve  in  any  quantity  of  water. 

Old-Fashioned  Size:  Many  old-fashioned  size  makers  still 
adhere  to  the  practice  of  using  excessive  quantities  of  soda  ash 
and  cooking  the  size  so  thoroughly  that  all  the  rosin  is  converted 
into  soap  and  no  “free  rosin”  remains.  They  test  by  dissolving 
in  water,  and  if  the  size  gives  no  “yellow  milk  color”  they  cook 
again.  This  is  very  wasteful  of  soda  ash  and  alum.  Old-fash¬ 
ioned  size  makers  call  modern  high  free  rosin  size,  “raw  size.” 

Adding  Size  to  the  Beaters. 

The  size  should  be  diluted  with  water  before  adding  to  the 
beaters.  The  most  convenient  proportion  is  i  gallon  of  size  to  4 
gallons  of  water,  if  ordinary  size  is  used.  If  a  high  free  rosin 
size  is  used  correspondingly  more  water  will  have  to  be  added. 

Size  should  always  be  added  to  the  beaters  before  the  alum — 
never  after,  or  at  the  same  time.  The  size  should  be  furnished 
when  the  stock  is  thin. 

If  any  quantity  of  size  is  kept  on  hand,  the  tank  in  which 


246  MODERN  PULP  AND  PAPER  MAKING 

it  is  kept  should  be  provided  with  an  agitator.  It  is  advisable 
to  keep  enough  size  on  hand  that  the  beaters  will  never  be  furn¬ 
ished  from  too  freshly  made  size.  Moderately  old  size  is 
better. 

If  clay  is  used,  it  is  a  good  plan  to  mix  together  the  size  and 
clay  before  adding  to  the  beater,  and  then  to  strain  both.  How¬ 
ever,  if  the  clay  and  water  are  mixed  in  a  large  tank  and  con¬ 
veyed  to  the  beaters  by  pipes  this  is  not  advisable.  It  works  well 
when  the  clay  is  mixed  with  water  in  a  small  mixing  tank 
above  each  beater. 

Adding  the  alum  before  the  size  is  properly  dissolved  is  a 
frequent  cause  of  size  spots.  These  are  frequently  blamed 
on  the  composition  of  the  size. 

Foaming  causes  trouble  if  the  stock  is  warm.  Little  trouble 
is  experienced  from  this  cause  if  the  stock  is  beaten  cold.  In 
heavy  sized  paper  it  is  sometimes  advisable  to  mix  a  little  tallow 
with  the  size  during  the  cooking.  This  tends  to  prevent  foaming. 
Some  paper  makers  add  kerosene  to  prevent  foaming,  but  this 
is  inadvisable. 

Size  in  Newsprint. 

Some  paper  makers  claim  that  i  pint  of  size  to  a  1,000  lb. 
beater  is  of  advantage  in  making  newsprint.  It  helps  the  fibre 
to  lie  down  in  moist  weather.  It  is  also  claimed  that  it  aids  the 
retention  of  clay  in  the  paper.  This  is  undoubtedly  true  if  a  large 
amount  of  size  be  added,  but  experiments  have  proven  that  the 
amounts  usually  added  in  making  newsprint  have  no  effect  on 
the  retention  of  the  clay  at  all.  Alum  has  much  more  effect 
in  this  regard. 

It  is  an  undoubted  fact  that  the  use  of  size  in  news  causes 
trouble  with  foam,  slime,  etc.,  and  as  very  good  news  can  be 
made  without  size,  it  would  seem  better  practice  to  leave  it  out 
rather  than  to  put  it  in  on  the  supposition  that  it  may  do  some 
good. 

General  Considerations  about  Sizing. 

Many  conditions  influence  good  sizing  results.  It  is  well 
known  that  free  stock  is  more  difficult  to  size  than  slow  stock. 
This  is  due  because  the  finer  meshes  of  the  slow  stock  retain  the 
particles  of  rosin  almost  completely  while  the  coarse  meshes 
formed  by  the  free  stock  permit  much  of  the  size  to  pass  through 
and  be  lost.  Sizing  is  quite  a  sensitive  operation  and  almost 
any  change  in  the  conditions  under  which  a  sheet  of  paper  is 
made  will  produce  some  effect  in  the  sizing. 

We  have  observed  that  a  sheet  which  has  been  running  for 
some  time  with  satisfactory  results  as  to  sizing  became  “slack 
sized”  when  the  machine  was  speeded  up.  The  amount  of  size 
had  to  be  increased  25  per  cent  in  order  to  get  the  same  result 
as  before. 


THE  BEATER  ROOM 


247 

Also  we  noted  in  making  hangings  out  of  a  coarse  pulp  espe¬ 
cially  ground  for  the  purpose  that  much  more  size  was  re¬ 
quired  to  produce  the  same  result  than  when  “news  pulp”  was 
used  for  the  hangings.  Having  run  out  of  the  special  “hanging 
pulp”  news  pulp  was  substituted  and  it  was  apparent  that  the 
paper  was  too  hard  sized  and  the  amount  had  to  be  cut  down 
considerably.  As  soon  as  regular  “hanging  pulp”  was  again 
used  more  size  had  to  be  used. 

Grinding,  beating,  Jordaning  all  have  a  decided  influence  on 
the  quantity  of  size  necessary  to  produce  good  results.  It  is 
also  probable  that  sizing  is  influenced  by  the  shake,  suction,  dry¬ 
ers,  etc.,  and  in  fact  almost  by  every  step  in  paper  making. 

Alum. 

Alum — in  the  usage  of  the  paper  maker — does  not  mean 
the  alum  of  the  chemist,  which  is  the  crystallized  double  sul¬ 
phate  of  aluminum  and  potash.  Paper  makers  use  the  term 
alum  to  denote  aluminum  sulphate,  Al^  (804)3  18  H2O.  The 
true  alum  was  once  used  in  paper  making,  but  has  been  replaced 
by  aluminum  sulphate  which  is  cheaper  and  stronger  in  alumina. 
The  aluminum  sulphate  or  paper  makers’  alum  of  commerce  is 
not  a  definite  chemical  compound,  different  makers  driving  off 
different  amounts  of  the  combined  water  before  the  product  is 
placed  on  the  market.  The  best  commercial  product  on  the 
market  today  contains  22  per  cent  alumina,  AI2O3  which  is 
equivalent  to  73  per  cent  sulphate  of  alumina,  Al2( 864)3. 

Commercial  alum  is  generally  prepared  from  bauxite,  a  nat¬ 
urally  occurring  hydrous  oxide  of  aluminum.  Pulverized  bauxite 
is  agitated  with  50^"  Be.  sulphuric  acid  in  lead  lined  tanks. 
The  mixture  becomes  very  hot  during  the  reaction,  after  which 
it  is  diluted  with  water,  allowed  to  become  cool  and  to  stand 
long  enough  to  deposit  silica  and  other  impurities.  The  clear 
liquor  is  then  decanted  off,  concentrated  with  heat,  and  when 
thick  enough,  run  out  onto  marble  slabs,  where  it  crystallizes  in 
a  mass  which  is  broken  up,  packed  and  sold. 

As  bauxite  always  contains  some  iron,  the  commercial  alum  is 
rarely  free  from  iron.  The  iron  is  frequently  reduced  to  the 
ferrous  condition  with  zinc  before  the  alum  is  crystallized, 
but  this  proceedure  is  useless  from  the  paper  makers’  point  of 
view  as  the  iron  soon  oxidizes  up  again  and  colors  the  paper  in 
which  it  is  found. 

A  good  alum  should  contain  very  little  insoluble  matter,  not 
over  one-half  of  i  per  cent.  More  insoluble  matter  indicates  that 
the  alum  has  been  made  in  a  hurried  and  careless  manner. 

Free  sulphuric  acid  is  objectionable  in  an  alum.  It  decom¬ 
poses  the  size,  corrodes  the  wire,  disintegrates  the  felts  and 
attacks  every  pipe  and  vessel  it  comes  in  contact  with.  It  is  pos¬ 
sible  to  obtain  from  the  manufacturers  alum  quite  free  from 
free  sulphuric  acid  and  this  should  be  insisted  on. 


248  MODERN  PULP  AND  PAPER  MAKING 

Other  things  being  equal,  the  important  point  about  an 
alum  is  the  alumina  content,  although  the  efficiency  of  the  alum 
cannot  be  absolutely  judged  by  this  factor. 


ANALYSES  OF  ALUMS 

Selected  from  Griffin  and  Little  (Except  No.  4) 


(i) 

(2) 

(3) 

(4) 

Insoluble  in  Water . 

.  10.61 

0.67 

0.  II 

0.02 

Alumina  (AI2O3) . 

22.37 

11.64 

22.02 

Iron  Oxide  (FeO . 

0.46 

0.06 

none 

Iron  Oxide  (Fe203) . 

.  1.08 

0.08 

1. 17 

o.oi 

Zinc  Oxide  (ZnO) . 

.  none 

3.80 

none 

none 

Soda  (Na20) . 

none 

4-75 

0.72 

Magnesia  (MgO) . 

.  none 

none 

0-45 

none 

Combined  Sulphuric  Acid . 

.  37-36 

45.28 

35-98 

45 -36 

Free  Sulphuric  Acid . 

.  1.08 

none 

5-13 

none 

Water  by  difference . 

.  34-21 

27-34 

40.71 

31-87 

Sizing  Test  (parts  of  neutral  rosin  size 

precipitated  by  one  part  of  the  alum)  3 . 47 

3-64 

3-19 

.... 

Notes;  In  Sample  (i)  the  high  percentage  of  water  insoluble  material  m- 
dicates  that  the  raw  material  was  not  entirely  dissolved  by  the  acid,.  The 
free  acid  is  also  too  high  in  this  sample,  and  the  iron.  Such  an  alum  is  more 
suitable  for  water  softening  than  for  paper  making.  (2)  is  a  better  alum  but 
the  iron  is  too  high.  (3)  is  a  very  poor  alum,  the  alumina  being  very  low  and 
the  percentage  of  free  acid  being  abnormally  high.  (4)  is  one  of  the  best 
commercial  alums  on  the  market  today.  The  alumina  is  high,  the  iron  almost 
negligible  and  no  trace  of  free  acid  present.  It  is  interesting  to  note  that 
apparently  a  higher  alumina  content  than  that  required  for  the^  neutral  sub 
phate  has  no  effect  on  the  sizing  efficiency  of  the  alum,  as  (2)  in  which  the 
alumina  is  very  high  is  not  appreciably  more  efficient  than  (3)  in  which  the 
alumina  is  very  low. 


Furnishing  Alum. 

Sometimes  dry  alum  is  put  in  the  beater,  but  it  is  better 
to  make  up  a  solution  of  alum  and  use  that.  The  solution  can  be 
kept  in  a  measuring  box  above  the  beaters  and  connected  below 
with  a  lead  pipe  leading  to  the  beater.  The  alum  solution  is 
run  into  the  measuring  box  and  thence  into  the  beater.  The 
solution  may  be  of  any  strength,  but  i  pound  to  a  gallon  is  a 
convenient  strength. 

Function  of  Alum  in  Paper  Making. 

It  is  frequently  said  that  alum  is  added  to  size  the  paper. 
That  is  not  correct.  The  true  purpose  of  alum  is  to  precipitate 
the  dissolved  rosin  in  the  size  on  the  fibres  of  the  paper.^^ 
is  sometimes  called  “setting”  the  size.  It  also  sets  or  fixes 
certain  colors,  making  them  stronger  and  brighter,  as  certain 
reds  and  blues.  However,  it  weakens  certain  other  colors,  such 
as  yellows  and  greens,  If  it  is  necessary  to  make  a  heavily 


THE  BEATER  ROOM 


•  249 

sized  yellow  paper  it  js  best  to  experiment  until  the  exact  amount 
of  alum  to  set  the  size  is  found  and  then  use  care  not  to  add 
any  more  than  that  as  it  will  weaken  the  color.  The  same 
hint  applies  to  many  other  colors.  However,  many  paper  makers 
have  the  idea  alum  strengthens  all  colors,  and  will  tell  you  it 
keeps  the  color  from  washing  out  of  the  paper,  and  when  they 
are  making  any  highly  colored  paper  they  will  be  very  liberal 
in  their  use  of  alum.  This  practice  is  based  on  no  scientific 
reason,  and  in  many  cases  is  absolutely  wrong.  The  dealers  in 
colors  can  usually  provide  information  as  to  how  they  should 
be  used,  and  unless  the  mill  is  provided  with  a  chemist  com¬ 
petent  to  work  such  things  out  on  a  truly  scientific  basis  it  is 
always  better  to  follow  the  color  dealer’s  instructions  in  detail. 

Too  much  alum  renders  the  paper  brittle,  causes  it  to  loose 
moisture  rapidly,  and  is  a  cause  of  rapid  deterioration.  Some¬ 
times  excessive  amounts  of  alum  are  added  to  impart  a  stiffness 
and  rattle  to  the  paper  but  this  is  bad  practice  as  it  will  cause 
the  troubles  described  above  and  the  desired  effect  can  be  se¬ 
cured  in  other  ways —  e.  g.,  by  the  use  of  silicate  of  soda, 
starch,  etc. 

Excess  of  alum  is  also  hard  on  the  wire  and  felts,  especially 
the  dryer  felts.  The  rottenness  of  felts,  frequently  attributed 
to  burning  or  scorching  on  the  dryers  is  due  to  a  large  extent 
to  the  accumulation  of  alum.  The  combined  action  of  the 
alum  and  the  heat  of  the  dryer  will  soon  destroy  the  felt. 

In  addition  to  setting  the  size,  alum  has  a  clarifying  effect 
on  the  water.  If  water  is  turbid  due  to  the  presence  of  clay, 
etc.,  it  cannot  be  filtered  bright  as  this  slime  will  either  pass 
through  the  filter  or  else  will  completely  stop  up  the  pores  of 
the  filter  so  no  water  passes  through  at  all.  Alum  causes  the 
dirt  in  the  water  to  coagulate  so  that  it  falls  down  in  granules, 
leaving  the  water  above  clear  and  bright.  Now,  in  paper  mak¬ 
ing  the  alum  exerts  this  same  property  and  much  clay  and  fine 
fibre  that  would  otherwise  be  carried  off  with  the  water  is 
coagulated  and  held  in  the  web  and  is  less  likely  to  be  sucked 
out  by  the  suction  boxes  or  to  drain  through  the  wire.  This 
is  why  alum  aids  in  the  retention  of  clay,  a  fact  that  we  alluded 
to  when  discussing  the  use  of  clay  as  a  filler. 

Hardening  Action  of  Alum. 

Alum  tends  to  harden  all  organic  substances.  This  is  some¬ 
times  alluded  to  as  the  sizing  effect  of  alum,  but  this  is  not 
correct,  because  sizing  renders  a  paper  impervious  to  moisture 
and  while  alum  makes  a  paper  hard  and  stiff  it  does  not  make  it 
any  more  resistant  to  moisture  than  if  none  had  been  used. 
The  general  feel  of  such  a  paper  is  as  if  it  had  been  sized,  but 
It  has  none  of  the  real  properties  of  a  properly  sized  paper. 

It  is  sometimes  desirable  to  make  a  very  well  sized  soft 
paper,  as  for  wall  paper  and  hangings.  In  order  to  do  this 


2^0  MODERN  PULP  AND  PAPER  MAKING 

we  use  a  liberal  amount  of  size  and  less  alum  than  is  neces¬ 
sary  to  completely  fix  the  size,  letting  some  of  the  size  wash 
out  This  wastes  some  size  and  causes  a  little  trouble  with 
foam  on  the  screens,  but  no  other  way  of  attaining  the  desired 
result  has  been  devised.  If  enough  alum  is_ added  to  completely 
fix  the  size,  the  paper  is  too  hard  and  brittle  for  satisfactory 

hangings. 


Alum  and  Foaming. 

Alum  prevents  to  some  extent  the  foaming  caused  by  size, 
especially  new  size  from  which  the  liquor  has  not  been  well 
separated.  In  cases  where  an  excess  of  alum  is  not^  objection¬ 
able  this  method  of  preventing  foam  may  be  permissible,  but 
as  a  rule  it  is  better  to  kill  the  foam  with  a  spray  of  water  or 
an  air  blast. 


Alum  and  Pitch. 

Alum  tends  to  keep  the  wire  of  the  paper  machine  bright. 
This  is  because  of  a  slight  corrosive  action  on  the  wire,  which 
is  increased  if  the  alum  contains  any  free  sulphuric  acid.  A 
wire  will  last  longer  if  excessive  alum  is  not  used,  but  when 
pitch  is  present  to  any  extent  the  use  of  alum  to  prevent 
sticking  seems  an  instance  of  permitting  a  slight  evil  to  cure 
a  much  greater  one.  However,  the  use  of  alum  for  this  purpose 
should  be  with  discretion  as  too  much  alum  will  have  a  ver>' 
bad  effect  on  the  felts. 


Alum  and  Water. 

If  the  water  used  in  the  mill  is  hard,  i.  e.,  if  it  contains 
salts  of  lime  or  magnesia  in  solution,  a  larger  amount  of  alum 
than  usual  will  have  to  be  used  to  properly  set  the  size  1  his  is 
because  some  of  the  alum  is  used  up  in  precipitating  the  lime  or 
magnesia  salts,  as  previously  referred  to  in  this  chapter  Some 
paper  makers  add  alum  in  excess  of  the  amount  required  to  set 
the  size  purposely  to  secure  this  effect,  as  if  the  lime  and 
nesia  compounds  are  present  in  the  water  when  the  size  is  added 
they  will'  precipitate  the  size  as  a  flaky  precipitate  of  resmates 
of  lime  and  magnesia  which  has  no  sizing  value  and  simply 
wastes  that  much  rosin  as  well  as  precipitating  an  insoluble 

powder  that  is  troublesome  in  the  stock.  •  •  + 

When  alum  is  used  in  this  way  the  general  practice  is  to 
determine  in  the  laboratory  the  amount  of  alum  needed  to  soften 
the  water,  and  then  add  that  amount  to  the  beater  before  furn¬ 
ishing  the  size.  Then,  after  the  size  is  furnished,  the  amount 
of  alum  necessary  to  set  the  size  is  furnished. 

However,  a  much  more  modern  and  efficient  way  of  produc¬ 
ing  the  same  results  is  the  installation  of  a  water  softening  p  ant, 
if  the  mill  is  located  in  a  district  where  the  water  supply  is  at 
^11  hard.  Such  a  plant  furnishes  perfectly  soft  water  for  the 


THE  BEATER  ROOM  251 

paper  mill  and  also  for  the  boilers  and,  in  mills  where  varieties  of 
paper  are  being  produced  where  hardness  of  water  would  have 
a  serious  detrimental  effect,  will  prove  economical  in  the  long 
run.  Efficient  water  softening  plants  that  require  little  atten¬ 
tion  are  offered  by  a  number  of  firms  and  we  will  describe  some 
of  the  leading  types  of  such  plants  in  a  subsequent  chapter 
when  speaking  of  water  supply. 

Caution  Regarding  the  Use  of  Alum  and  Other  Chemicals. 

Paper  making  is  largely  a  mechanical  process  and  the  quality 
of  the  finished  product  is  dependent  primarily  on  the  character 
of  the  stock  and  the  manner  in  which  it  is  manipulated  in  the 
beaters  and  on  the  machine.  The  paper  can  be  no  better  than 
the  fibre  (whether  it  be  sulphite,  ground  wood,  rag  or  any¬ 
thing  else),  which  is  put  into  it.  Compared  with  these  factors 
the  quantity  of  chemicals  added  is  insignificant. 

When  the  quality  of  the  paper  is  not  what  is  desired  the 
remedy  will  usually  be  found  in  the  operation  of  the  beaters 
or  the  machine  (the  shake,  the  dryers,  the  operation  of  the 
suction  boxes,  etc.),  rather  than  in  d^osing  the  stock  with  chem¬ 
icals  or  trying  to  make  good  paper  out  of  poor  stock  by  using 
clay,  alum,  silicate  of  soda,  etc. 

^  It  is,  o.f  course,  necessary  for  one  to  do  everything  pos¬ 
sible  to  get  the  best  results  from  a  given  stock  and  in  some 
cases  (e.  g.,  where  the  wood  pulp  fibre  is  too  coarse  and  hence 
the  paper  will  not  retain  a  good  surface),  it  is  all  right  to  use 
chemicals  liberally ;  but  to  make  a  regular  practice  of  that  in¬ 
stead  of  getting  to  the  root  of  the  matter  and  finding  out  what 
IS  wrong  with  the  stock  or  with  the  operation  of  the  mechanical 
equipnient  of  the  mill,  would  be  very  bad  practice. 

It  is  a  good  rule  that  whenever  the  appearance  of  a  sheet  can 
be  improved  by  mechanical  means  to  do  so  rather  than  resort 
to  the  use  of  chemicals. 

To  Test  How  Much  Alum  is  Necessary  to  Set  a  Given  Quan¬ 
tity  of  Size  in  an  Engine.  ^ 

Furnish  the  engine  as  usual  with  everything  except  clay, 
color  and  alum.  Have  the  stock  rather  thin,  so  that  it  will  travel 
fast  around  the  engine. 

Dissolve  5  pounds  of  alum  in  hot  water  in  a  wooden  pail, 
and  pour  the  solution  into  the  engine,  allow  it  to  mix  for 
about  15  or  20  minutes  and  then  test  it  as  follows: 

Have  a  small  box  made  holding  about  a  quart,  and  covered 
at  the  bottom  with  a  piece  of  fine  wire  cloth.  Fill  this  with 
stock  from  the  engine,  and  allow  the  water  to  run 
^ooks  clear,  then  catch  about  a  half  a  tumbler  full 
of  It.  Do  not  prps  the  water  out  of  the  pulp,  but  let  it  drain 
off  naturally,  it  will  then  be  clearer.  Add  a  little  litmus  solution 
to  the  tumbler,  and  if  enough  alum  has  been  added  the  solution 


252  MODERN  PULP  AND  PAPER  MAKING 

will  turn  red.  If  it  is  blue  dissolve  5  pounds  more  of  alum, 
add  it  as  before  and  test  at  the  end  of  another  15  or  20  minutes. 
Continue  this  until  the  clear  liquid  turns  the  litmus  a  distinct 

red.  ,  •  r  1 

When  large  quantities  of  size  are  used,  testing  after  the 

addition  of  each  5  pounds  of  alum  will  be  close  enough.  If 
only  a  little  size  is  used,  however,  the  alum  should  be  added 
in  portions  of  i  pound  at  a  time,  in  order  to  determine  the 
proper  amount  with  more  accuracy. 

The  litmus  solution  is  made  fresh  before  the  test,  by  dis¬ 
solving  a  few  lumps  of  the  dry  litmus  in  a  half  tumbler  of  hot 

water.  . 

A  piece  of  cheese  cloth  makes  a  good  substitute  for  the 
wire  screen.  Do  not  squeeze  the  water  out,  however,  but  let 
it  run  naturally. 

The  amount  of  alum  necessary  to  set  a  given  quantity  of 
size  varies  at  different  mills,  owing  to  the  different  kinds  of 
water.  Also  the  quantity  of  alum  necessary  for  $  gallons  of 
size  is  not  five  times  as  much  as  would  be  required  for  one 
gallon,  because  the  water  itself  uses  up  some  alum.  Thus,  for 
example,  it  might  be  found  that  when  five  gallons  of  size  were 
furnished,  15  pounds  of  alum  would  be  necessary,  while  when 
only  one  gallon  of  size  was  furnished,  five  pounds  of  alum  might 
be  required  instead  of  only  three  pounds. 

It  will  also  be  observed  that  when  there  is  not  enough  alum 
to  set  the  size,  the  water  drawing  away  from  the  stock  will  have 
a  milky  appearance,  while  when  enough  alum  has  been  added, 
the  water  will  draw  away  quite  clear.  Clay  would  make  the 
water  a  little  milky,  so  it  is  best  to  leave  out  the  clay  in  making 
these  tests. 

Two  or  three  of  these  tests  performed  with  different  quan¬ 
tities  of  size  will  show  once  for  all  the  quantities  of  alum  re¬ 
quired  for  different  quantities  of  size  at  any  one  mill,  and  any 
more  alum  which  might  be  added  is  wasted  in  case  there  is  no 
other  object  in  adding  alum  except  that  of  setting  the  size. 


Silicate  of  Soda. 

This  chemical  is  sometimes  known  as  water  glass.  It  is 
generally  sold  in  solution  in  barrels  or  drums.  A  50  per  cent 
solution"  is  ordinarily  used,  but  any  required  concentration  can 
be  obtained  from  the  makers,  or  the  solid  silicate  can  be  ob¬ 
tained.  This  chemical  imparts  a  hardness  and  rattle  to  paper 
that  makes  it  valuable  for  use  in  certain  writing  papers.  It 
tends  to  set  size  just  like  alum.  It  should  not  be  used  in 
conjunction  with  alum  as  the  alum  will  yield  a  heavy  precipitate 
with  the  silicate  which  will  cause  trouble.  Silicate  of  soda  is 
also  used  in  making  certain  boards  and  paper  specialties  such  as 
corrugated  container  board,  on  account  of  its  adhesive  and  grease¬ 
proofing  qualities. 


THE  BEATER  ROOM 


253 


Starch. 

Various  starches  are  used  in  the  paper  industry,  such  as 
corn  starch,  wheat  starch,  potato  starch,  etc.  Starch  is  used 
for  its  hardening  and  stiffening  action ;  also  because  it  aids  in 
the  production  of  certain  highly  finished  surfaces  when  the 
paper  is  calendered. 

Some  paper  makers  add  the  starch  directly  to  the  beaters 
and  others  mix  it  with  the  size.  It  seems  to  exert  certain 
beneficial  properties  on  the  rosin  of  the  size,  enabling  the 
particles  of  rosin  to  become  better  attached  to  the  fibres  of  the 
stock. 

According  to  J.  Traquair’^  corn  starch  is  not  the  best  to  use, 
a  mixture  of  starches  being  better,  and  i  lb.  starch  should  be 
boiled  with  2  gallons  of  water  and  the  mixture  kept  at  a  little 
less  than  the  boiling  point  for  from  15  to  20  minutes,  after 
which  the  starch  is  ready  to  be  added  to  the  beater.  Accord¬ 
ing  to  this  authority  the  retention  of  starch  is  about  50  per 
cent. 

However,  starch  is  not  much  used  in  paper  making,  its  use 
being  confined  to  certain  high  class  writing  and  book  papers, 
also  a  little  being  used  in  cigarette  paper. 

There  are  various  prepared  starches  in  use  made  by  treating 
ordinary  starch  with  alkaline  and  acid  solutions.  Undoubtedly 
many  of  these  are  of  use  in  making  high  grade  papers,  but  in 
general  their  use  is  prohibited  by  the  expense. 

Colors, 

It  is  hardly  within  the  province  of  this  book  to  deal  at  great 
length  with  so  special  and  highly  technical  a  subject  as  the 
coloring  of  paper.  Also  this  is  a  branch  of  paper  making 
where  personal  experience  is  specially  necessary.  However, 
some  general  remarks  about  the  coloring  of  paper  may  prove 
helpful. 

Color  is  almost  always  added  to  the  stock  in  the  beater,  that 
being  the  chief  time  during  the  paper  making  process  when  there 
is  an  opportunity  to  color  the  fibres. 

The  coloring  of  paper  has  never  received  the  same  attention 
that  the  coloring  of  textile  fabrics  has.  It  is  unusual  to  find 
men  around  a  beater  room  who  are  as  skilled  and  expert  in 
the  use  of  colors  as  the  average  textile  dyer.  The  average  paper 
maker  regards  color  as  a  minor  item  in  his  responsibilities. 

However,  almost  all  paper  has  at  least  a  little  color  added 
to  it.  The  bleach  is  seldom  relied  on  to  give  a  satisfactory 
white  color.  Even  newsprint  has  added  to  each  beater  usually 
a  gill  or  two  of  blue  and  red  to  improve  the  appearance. 

The  color  of  the  stock  in  the  beater  is  usually  deeper  than 
it  will  be  In  the  finished  paper.  One  method  of  matching  the 

'Technical  Association  Papers,  1918,  pg.  43. 


254  MODERN  PULP  AND  PAPER  MAKING 

color  is  to  reduce  the  sheet  to  be  matched  to  pulp,  then  making 
the  pulp  in  the  beater  the  same  color.  By  squeezing  dry  a 
handful  of  stock  from  the  beater  some  idea  can  be  gained  as 
to  how  the  color  will  be  in  the  finished  sheet. 

An  experimental  beater  and  a  frame  for  making  sample 
sheets  by  hand  will  be  found  useful  in  every  mill  where  colored 
papers  are  being  made.  In  general,  the  reliable  dealers  in  colors 
and  dyes  can  be  depended  on  to  give  excellent  help  and  advice 
in  matching  colors.  Many  of  these  firms  maintain  experimental 
paper  beaters  and  machines  for  testing  out  their  colors  and 
solving  their  customers’  problems. 

The  coloring  materials  used  in  the  paper  industry  may  be 
divided  into  pigments,  or  mineral  colors  (however  a  few  pig¬ 
ments  are  non-mineral  in  nature),  which  are  distinguished^  by 
being  insoluble  in  water,  and  dyestuffs,  mostly  artificial  in  origin 
and  usually  spoken  of  by  the  general  title  of  ‘‘‘aniline  dyes.” 

Pigments  color  the  stock  by  becoming  enmeshed  with  the 
fibres  in  the  beater.  The  size  and  alum  helps  the  fibres  to  retain 
the  pigments,  which  adhere  in  small  particles  to  the  surface  of  the 
fibre.  Pigments  do  not  penetrate  the  substance  of  the  fibre  as 
do  dyestuffs.  There  is  probably  no  chemical  action  between 
the  cellulose  of  the  fibre  and  the  pigment,  whereas  in  the  use 
of  dyestuffs  the  combination  seems  to  be  more  chemical  than 
mechanical. 

The  percentage  of  retention  of  a  pigment,  and  therefore  the 
degree  to  which  the  paper  is  colored,  depends  on  the  manner 
of  sizing,  the  amount  of  alum  used,  the  specific  gravity  of  the 
pigment  and  the  nature  of  the  stock.  Slow  stock  gives  a  higher 
retention  than  free  stock.  Also  the  operation  of  the  paper 
machine,  and  whether  or  not  suction  couch  rolls  are  used  affects 
the  retention  of  pigment. 

Pigments,  if  used  in  any  quantity,  have  exactly  the  same 
action  as  clay.  In  fact,  they  may  be  considered  as  colored 
clays.  Just  as  too  much  clay  will  weaken  the  paper,  so  will 
too  much  pigment.  Many  pigments  contain  grit.  All  pigments 
to  be  used  should  be  passed  on  by  the  laboratory  to  ascertain 
that  they  are  free  from  grit,  which  will  cause  pin  holes  in  the 
paper  and  also  will  injure  the  wire  and  felt  and  the  calender 
rolls. 

Some  of  the  commonest  pigments  are  ultramarine,  Prussian 
blue,  chrome  yellow,  red  oxide,  yellow  oxide,  umber,  etc.  All 
of  these  vary  in  their  fastness  to  light  and  to  alum.  For  the 
action  of  alum  on  colors,  see  the  section  of  this  chapter  dealing 
with  alum. 

Owing  to  their  being  more  powerful,  more  varied  and 
easier  handled,  dyestuffs  have  largely  replaced  pigments.  More¬ 
over,  they  have  no  effect  on  the  strength  of  the  sheet. 

Dyestuffs:  Whether  one  speaks  of  aniline  dyestuffs,  ^  syn¬ 
thetic  dyestuffs  or  dyes,  coal  tar  dyes  or  colors,  etc.,  it  is  all 


THE  BEATER  ROOM 


255 


the  same  product  that  is  meant.  They  are  all  made  from  deriva¬ 
tives  of  coal  tar  by  a  series  of  complicated  processes  that  is  one 
of  the  triumphs  of  applied  chemistry.  The  first  such  dye  was 
invented  by  Sir  William  Perkin  in  1856,  since  which  date  thou¬ 
sands  of  others  have  been  invented. 

Different  manufacturers  sell  their  dyes  of  different  strengths. 
They  are  practically  never  placed  on  the  market  full  strength. 
They  are  almost  universally  sold  on  the  basis  of  samples.  The 
names  given  to  these  dyes  have  no  logical  basis.  Each  manu¬ 
facturer  will  give  his  dyes  some  individual  name.  Letters 
placed  after  the  name  of  the  dyestuff  generally  imply  a  certain 
shade,  for  instance  R  placed  after  the  name  of  a  blue  means 
that  it  has  a  reddish  shade. 

Dyestuffs  are  divided  into:  (i)  Basic  dyestuffs,  (2)  Acid 
dyestuffs,  (3)  Direct  dyestuffs,  (4)  Vat  dyestuffs. 

Basic  dyes  are  not  very  fast  to  light  and  are  hard  to  use 
unless  perfectly  soft  water  is  at  hand.  With  hard  water  they 
give  the  paper  a  spotty  or  mottled  appearance.  These  dyes 
require  no  alum  to  set  them.  Auramine  is  a  typical  example 
of  these  dyes. 

Acid  dyes  must  be  set  with  alum.  They  are  faster  to  light 
than  basic  dyes.  Unlike  basic  dyes  they  will  resist  comparatively 
high  temperatures  without  change.  They  also  work  better  if 
the  water  is  at  all  hard. 

Direct  dyes  do  not  require  any  alum  or  other  chemical  to 
set  them.  They  do  not  work  well  with  hard  water.  They  enter 
into  direct  chemical  combination  with  the  fibre  and  so,  are 
suitable  for  use  with  unsized  paper,  such  as  blottings.  They 
are  faster  to  light  than  either  the  basic  or  add  colors.  These 
are  the  dyes  that  are  known  in  the  textile  industry  as  cotton 
dyes. 

Vat  dyestuffs  are  little  used  in  the  paper  industry.  They 
are  practically  pigments  of  synthetic  origin.  So  far  few  vat  dyes 
have  been  made  in  America,  whereas  almost  all  basic,  acid  and 
direct  dyestuffs  are.  Vat  dyes  are  more  expensive  than  the 
others. 

Notes  on  Coloring  Paper  with  Dyestuffs. 

Test  dyes  to  ascertain  that  a  mixture  is  not  being  used. 
Mixtures  do  not  give  uniform  and  satisfactory  results.  A  simple 
test  for  a  mixture  is  to  take  a  pinch  of  the  dyestuff  on  a  knife 
or  coin  and  blow  it  sharply  onto  a  piece  of  filter  or  blotting  paper 
dipped  in  water  containing  a  little  acid.  If  the  dye  is  a  mixture 
usually  spots  of  individual  colors  can  be  seen  where  the  tiny 
separate  particles  fall. 

It  is  better  to  dissolve  the  dyes  to  a  liquid  or  to  a  paste 
before  adding  them  to  the  beater.  Dry  dyes  added  to  the  beater 
are  not  so  effective  as  some  of  the  dyestuff  is  wasted  and  the 
effect  is  not  so  even. 


256  MODERN  PULP  AND  PAPER  MAKING 

Basic  colors  and  acid  colors  should  never  be  used  together. 
They  tend  to  coagulate  each  other. 

Basic  colors  should  not  be  mixed  or  used  together  with 
direct  colors. 

Acid  colors  can  be  used  with  direct  colors,  but  not  with 
basic  colors. 

Direct  colors  can  be  used  with  acid  colors,  but  not  with 
basic  colors. 

Excess  of  alum  is  bad  for  all  colors.  Just  the  right  amount 
to  use  should  be  determined. 

Good  results  can  sometimes  be  used  when  a  very  full  shade 
is  desired  by  first  dyeing  the  stock  with  an  acid  color  and  then 
submitting  it  to  a  second  dyeing  with  a  basic  color.  This  will 
give  a  better  color  than  could  be  obtained  with  an  acid  dye 
alone,  and  it  will  be  faster  to  light  than  if  a  basic  dye  alone 
were  used. 

In  coloring  mixed  stock,  such  as  ground  wood  and  sulphite, 
sometimes  the  ground  wood  will  take  the  dye  before  any 
sulphite  does,  producing  a  mottled  stock.  This  can  be  pre¬ 
vented  by  dyeing  the  ground  wood  first  in  a  separate  beater 
and  then  mixing  it  with  the  sulphite  which  has  already  been 
dyed. 

Mottled  papers,  for  instance,  mottled  blottings,  are  made 
by  dyeing  the  stock  strongly  in  two  or  more  separate  engines, 
then  mixing  just  before  the  stock  goes  on  the  machine. 

In  purchasing  colors  adulteration  should  always  be  guarded 
against.  Little  risk  is  incurred  if  the  colors  are  bought  from 
reliable  manufacturers,  but  as  colors  are  extensively  handled 
by  jobbers,  etc.,  large  amounts  of  highly  adulterated  colors  get 
on  the  market._  This  is  possible  because  of  the  high  concentration 
of  the  synthetic  dyes  and  also  because  of  the  temptation  offered 
by  cheap  colors.  As  a  rule  the  best  colors  will  be  found  the 
most  efficient  in  the  long  run  regardless  of  price. 

The  principal  adulterants  are  dextrine,  salt,  sugar  and  Glaub¬ 
er’s  salt.  None  of  these  are  harmful,  except  in  that  the  cus¬ 
tomer  is  paying  for  their  weight  at  the  price  of  a  dyestuff. 

_  Several  American  firms  are  now  manufacturing  dyestuffs 
suitable  for  the  paper  industry  quite  equal  to  anything  previously 
manufactured  in  Germany.  In  fact  ft  is  stated  that  as  a  result  of 
tests  some  of  these  dyestuffs  are  better.  It  is  not  likely  that 
American  dyestuffs  can  be  sold  quite  as  cheap  as  German  dye¬ 
stuffs  formerly  were,  and  it  is  altogether  likely  that  the  German 
dye  manufacturers  will  offer  their  products  at  a  very  low  price 
in  the  attempt  to  regain  their  lost  trade,  the  system  known  as 
“dumping.”  However,  it  is  very  essential  that  the  American  dye¬ 
stuff  industry  should  be  supported  and  if  the  textile,  leather, 
paper  and  other  dye  using  interests  will  co-operate  there  is  no 
reason  why  we  should  not  soon  have  satisfactory  domestic 
sources  of  every  essential  dyestuff. 


THE  BEATER  ROOM 


257 

Stock  Chests. 

In  the  basement  of  the  beater  room  are  a  number  of  stock 
chests.  These  are  for  receiving  the  stock  from  the  beaters  pre¬ 
paratory  to  sending  it  to  the  Jordans  or  other  refining  engines, 
or  to  the  paper  machines.  There  are  also  other  stock  chests  for 
receiving  stock  to  be  furnished  to  the  beaters.  Some  of  this 
stock  is  deckered  stock  received  direct  from  the  sulphite  mill  and 
some  of  it  is  stock  produced  by  disintegrating  laps  of  kraft  or 


Fig.  98. — Plan  and  elevation  of  two  typical  vertical  stock  chests. 


Other  pulp  with  shredders  and  pulpers.  Some  lap  stock  is  too 
hard  and  dry  to  feed  to  the  beaters  as  lap  stock  and  has  to 
be  mechanically  disintegrated  before  being  furnished.  This  is 
usually  done  with  shredders  and  pulpers. 

These  chests  vary  in  size  according  to  the  room  available, 
or  the  size  of  the  plant,  but  an  average  storage  chest  will  hold 
approximately  2.5  to  3  tons  of  air  dry  stock.  These  chests  are 
always  provided  with  agitators  to  keep  the  stock  of  uniform 
consistency  and  to  drive  an  agitator  of  the  usual  type  in  such  a 
chest  as  we  have  described  requires  about  4. 

The  stock  is  pumped  from  the  storage  chests  to  the  beaters 
by  a  centrifugal  pump  and  it  is  generally  advisable  to  get  this 
pump  down  as  low  as  possible  so  as  to  get  all  the  head  available 
and  also  to  have  the  suction  pipe  as  large  as  possible.  A  6-inch 


/ 


% 


Courtesy:  Mitts  &  Merrill,  Saginaw,  Mich. 

Fig.  loi.- — Shredder  for  disintegrating  frozen  or  dried  pulp  laps. 

plex  plunger  pump.  It  is  good  practice  to  have  this  pump  oi 
sufficient  capacity  to  do  the  work  at  a  low  speed.  For  a  ma¬ 
chine  of  from  30  to  45  tons  capacity  a  12  x  12  triplex  pump 
is  a  very  efficient  size.  This  pump  running  at  a  speed  of  ap- 


THE  BEATER  ROOM 


pump  should  have  an  8-inch  discharge  pipe  and,  if  possible, _  a 
12-inch  suction.  The  power  required  to  drive  such  a  pump  with 
piping  as  described  with  a  head  of  not  over  20  feet  will  be  ap¬ 
proximately  20  h. 


Courtesy:  Noble  S’  Wood  Machine  Co.,  Hoosick  Falls,  N.  Y. 

Fig.  100. — Type  of  agitator  used  in  horizontal  stock  chest. 

The  stock  usually  gravitates  from  the  beaters  to  the  storage 
chests  from  which  it  is  pumped  to  small  chests  located  just 
above  the  Jordans.  This  is  usually  done  with  a  duplex  or  tri- 


Courtesy:  Ryther  &  Pringle  Co.,  Carthage,  N.  Y, 

Fig.  102. — Belt  feed  type  of  shredder  in  which  the  stock  is  fed  on  to  an 
endless  belt  and  carried  beneath  serrated  blades  which,  revolving  in 
a  manner  peculiar  to  their  arrangement,  tear  off  the  stock  in  small, 
irregularly  shaped  pieces  and  carrying  same  over  a  bed  plate  beneath 
the  revolving  blades  which  is  provided  with  a  number  of  serrated 
segments,  serve  to  further  disintegrate  the  stock  and  discharge  same 
in  front  of  the  machine  into  a  hopper  leading  to  a  chest  or  what¬ 
ever  other  arrangement  may  have  been  provided  to  receive  same. 


Courtesy:  E.  D.  Jones  &  Sons  Co.,  Pittsfield,  Mass. 

Fig.  103. — Belt  driven  Jordan  engine. 
260 


THE  BEATER  ROOM 


261 

proximately  25  r.  p.  ni.  will  deliver  from  30  to  45  tons  per 
24  hours  with  a  power  consumption  of  about  15  h.p.  against 
a  25  or  30  foot  head.  The  suction  pipe  should  be  at  least  14 
inches  in  diameter  with  a  stock  gate  in  the  line,  also  a  “tee’ 
placed  near  the  pump  to  enable  the  operators  to  clean  the  suc¬ 
tion  in  case  it  clogs. 

The  Jordan  Engine. 

This  machine  consists  essentially  of  a  conical  cast-iron  shell, 
the  inside  of  which  is  fitted  with  long,  narrow  steel  bars,  and 
rotating  inside  this  conical  shell  is  a  conical  casting,  called  the 
“plug”  or  “runner,”  the  outside  surface  of  which  is  fitted  with 
long,  narrow  steel  bars,  or  “knives,”  each  resembling,  more  or 


Fig.  104. — Diagram  showing  construction  of  Jordan  engine. 


less,  the  runner  of  a  skate,  although  only  about  >4  inch  high 
and  about  of  the  same  width. 

The  runner  is  journaled  to  rotate  about  its  long  axis,  and — 
like  the  beater  roll — can  be  adjusted  to  clear  the  inside  plates  of 
the  shell  by  a  very  minute  distance.  This  adjustment  is  per¬ 
formed  by  means  of  a  hand-wheel  and  screw.  The  runner 
makes  from  300  to  350  revolutions  per  minute. 

The  bars,  or  knives,  both  on  the  shell  and  the  runner  are 
accurately  ground,  so  that  when  the  runner  is  properly  ad¬ 
justed,  each  knife  cuts' its  entire  length. 

But  this  contact  of  the  runner  with  the  inside  knives  is  not  a 
direct  or  right-angle  cut.  The  bars  are  so  arranged  as  to  de¬ 
liver  a  shearing  cut  to.  the  material,  in  somewhat  the  same 
fashion  that  the  blades  of  a  lawn-mozver  are  obliqued  against  the 
bed-plate.  These  engines  are  massive  affairs,  weighing  several 
tons,  and  requiring  a  driving-power  of  from^  75  250  h.p., 

depending  on  the  grade  of  paper  being  made.  Kraft  rag  and  jute 
stock  take  considerably  more  power  than  any  other  kind  or¬ 
dinarily  met  with,  on  account  of  their  long  fibre  and  heavy 
consistency. 


262  MODERN  PULP  AND  PAPER  MAKING 

The  Jordan  engine  gives  the  paper-stiifif  the  last  refining 
touch  before  it  goes  to  the  paper  machine.  Each  little  bundle 
of  fibres,  which  would  otherwise  clog  and  mar  the  final  result,  is 
separated  and  distributed  throughout  the  material  in  such  a 
manner  as  to  make  the  whole  stock  consistent  and  homogeneous. 

The  material  is  forced  into  the  small  end  of  the  cone,  and 
out  through  the  other  end,  having  been  compelled  to  pass 


Courtesy :  R,  D,  Jones  S'  Sons  Co.,  Pittsfield,  Mass. 

Fig.  105. — Motor  driven  Jordan  engine. 

through  the  very  small  space  between  the  plug  and  the  shell, 
and  between  the  whirling  knives.  From  the  large  end  of  the 
Jordan  it  passes  down  to  a  second  stuff-chest,  quite  similar  to^  the 
one  that  receives  the  stuff  from  the  beaters,  and  is  maintained 
in  suspended  state  until  the  paper  machine  is  ready  for  it. 

Sand  Trap. 

At  the  inlet  to  the  Jordan  a  sand  trap  should  be  provided 
to  keep  sand  and  grit  and  also  foreign  matter  such  as  nails, 
screws,  pieces  of  iron,  etc.,  out  of  the_  Jordan.  On  account 
of  the  nature  of  the  Jordan  such  material  would  soon  play 
havoc  with  the  machine.  It  is  important  that  these  traps  should 
be  kept  cleaned  out,  otherwise  they  are  of  no  use.  Sometimes  a 
powerful  magnet  is  built  into  the  sand-  trap  to  retain  pieces  of 
iron.  This  is  a  very  useful  device. 

Split-Shell  Jordans. 

A  recent  improvement  in  Jordan  construction  is  making  the 
shell  in  two  halves,  an  upper  and  a  lower,  meeting  along  a 
horizontal  line.  The  shell,  heads  and  packing  boxes  are  split, 
so  that  the  top  half  of  the  shell  can  be  lifted  off  when  it  is 


THE  BEATER  ROOM 


263 

necessary  to  make  repairs  to  the  engine.  In  this  way  the  plug 
can  be  refilled,  without  being  removed,  by  merely  rotating  it.  The 
top  segment  of  the  shell  is  provided  with  lugs  and  eye-bolts 
to  facilitate  lifting  it.  The  two  halves  are  carefully  machined 
so  that  they  come  together  with  a  water-tight  joint  and  fasten 
with  bolts.  This  type  of  engine  is  very  handy  when  space  is  at 
a  premium  as  it  can  be  placed  close  to  a  wall  or  in  any  other  posi¬ 
tion  without  allowing  end  room  for  drawing  out  the  plug. 

Marshall  Engine. 

The  Marshall  engine  is  another  refining  engine,  more  used 
in  England  than  in  America,  but  very  useful  for  making  certain 
classes  of  paper.  It  is  especially  good  for  preparing  long, 
strong  stock  for  thin,  tough  papers.  It  is  quite  similar  to  the 
Jordan,  except  that  after  the  stuff  has  passed  between  the  cone 
and  the  shell,  it  is  caused  to  pass  between  a  revolving  and  a 
stationary  disc,  both  being  provided  with  knives  or  bars.  The 
revolving  disc  is  attached  to  the  end  of  the  plug  and  the  sta¬ 
tionary  disc  is  fastened  to  the  inside  of  the  shell  head.  The 
disc  has  a  brushing  action  on  the  fibres  much  like  the  action  of 
the  roll  in  the  beater,  and  the  stock  emerges  from  the  machine 
free  from  chips  and  bundles  of  fibre  and  of  uniform  consistency. 


Courtesy ;  Downingtown  Manufacturing  Co.,  East  Downington,  Pa. 

Fig.  106. — Miller  duplex  beater. 


Miller  Duplex  Beater. 

This  beater  is  designed  on  the  principle  of  effecting  two  beat¬ 
ing  operations  for  every  circulation  of  the  stock  through  the  tub, 


264  MODERN  PULP  AND  PAPER  MAKING 

As  the  largest  part  of  the  power  required  in  any  beating  engine  is 
the  power  for  circulating  the  stock,  the  above  method  would  be  a 
distinct  advantage  provided  that  it  did  not  involve  too  complex 
a  mechanism.  The  builders  of  the  Miller  beater  seem  to  have 


Courtesy:  Downingtoivn  Manufacturing  Co.,  East  Downingtown,  Pa. 


Fig.  107. — Diagram  showing  construction  and  operation  of  Miller  duplex 

beater. 

solved  the  engineering  problems  involved  very  nicely  and  num¬ 
bers  of  these  beaters  are  giving  very  good  service. 

The  cut  represents  a  section  of  the  Miller  beater,  showing 
the  submerged  roll  and  the  front  and  rear  midfeathers  dividing 
the  tub  into  upper  and  lower  sections,  through  which  the  stock  is 


Courtesy:  Holyoke  Machine  Co.,  Holyoke,  Mass. 


Fig.  108. — Umpherston  beater. 

circulated  by  contact  with  the  roll  in  both  sections,  which  greatly 
increases  the  rapidity  of  the  circulation  and  makes  it  impossible 
for  the  stock  to  settle  or  lodge  in  any  portion  of  the  tub.  The 
location  of  bed-plates  both  below  and  above  the  roll  doubles  the 


THE  BEATER  ROOM 


265 

beating  capacity  of  the  engine.  The  roll  is  carried  in  double 
lighters  in  the  usual  manner.  The  top  bed-plate  is  likewise  car¬ 
ried  on  double  lighters,  which  are  connected  to  and  controlled  by 
the  roll  lighters  in  such  a  manner  that  the  top  plate  is  raised 
and  lowered  twice  as  fast  as  the  roll,  thus  preserving  an  equal 
distance  between  the  roll  and  both  plates.  In  addition  to  being 
used  for  various  sorts  of  paper  stock,  this  beater  has  proven  very 
efficient  in  beating  cotton  fibre  for  use  in  making  smokeless  pow¬ 
der.  This  beater  can  be  equipped  with  one  or  more  cylinder 
washers  just  as  in  the  case  of  the  usual  type  of  beater. 

Umpherston  Beater. 

In  the  Umpherston  type  of  beater  the  stock  is  caused  to  pass 
below  the  door  and  backfall  on  its  return  path  to  the  front  of  the 
roll.  This  machine  is  very  economical  of  door  space  and  it  is 


From  "Outlines  of  Industrial  Chemistry,"  Thorp,  Macmillan  Co, 

Fig.  109. — Diagram  showing  principle  of  Umpherston  beater. 

also  supposed  to  give  very  perfect  circulation  with  somewhat  less 
expenditure  of  power  than  the  usual  type  of  beater.  However, 
although  many  of  these  machines  are  in  successful  use,  as  is  also 
the  case  with  numerous  other  specially  designed  beaters,  the  ordi¬ 
nary  type  of  beater  will  be  found  in  the  majority  of  mills.  The 
Umpherston  beater  can  be  equipped  with  cylinder  washers  in  the 
same  manner  as  any  other  beater.  The  illustration  shows  an  en¬ 
gine  with  one  washer. 

Continuous  Beating. 

The  intermittent  nature  of  the  beating  operation  causes  a  cer¬ 
tain  waste  of  time,  power  and  stock,  as  well  as  a  duplication  of 
equipment  in  some  cases.  Various  efforts  have  been  made  to  get 
*  around  the  dlling  and  discharging  of  beaters  and  to  devise  a  con¬ 
tinuous  beating  process.  Provided  that  such  a  system  could  be 
worked  out  in  a  practical  manner  many  mills  could  reduce  the 
amount  of  beating  equipment  required  by  a  large  amount  since  un- 


266 


MODERN  PULP  AND  PAPER  MAKING 


der  the  intermittent  system  the  beaters  are  idle  as  far  as  produc¬ 
tion  is  concerned  a  large  fraction  of  the  time.  Also  in  some 
operations,  for  instance  the  reduction  of  waste  paper,  owing  to 
variations  in  kind  of  stock,  strength  and  other  conditions,  some 
of  the  stock  is  reduced  before  other  portions  are  ready  to  be 
discharged  from  the  beater  and  the  portions  done  first  are  beaten 
too  much  before  the  others  are  properly  disintegrated. 

The  Bird  Continuous  Beater  Attachment  is  typical  of  such 
appliances  and  is  intended  to  enable  any  ordinary  beater  to  be 
operated  continuously.  It  consists  of  a  specially  constructed  cyl¬ 
inder,  which  is  placed  in  the  beater  like  a  cylinder  washer,  with 
holes  of  a  proper  size  in  the  face  and  on  the  end  next  to  the  mid¬ 
feather.  The  end  next  to  the  side  of  the  beater  is  open  for  the 


Courtesy :  Claliin  engineering  Co.,  Lancaster,  Unw. 


Fig.  no. — Claflin  Continuous  Beater. 

discharge  of  the  beaten  stock  which  has  been  extracted  through 
the  holes  in  the  cylinder.  A  drain  is  cut  into  the  side  of  the  beater 
to  which  can  be  fitted  a  dam  which  will  regulate  the  level  of  the 
stock. 

Various  other  devices  of  the  same  kind  have  been  experi¬ 
mented  with  from  time  to  timei  They  have  found  their  chief 
application  in  working  up  waste  paper,  etc.,  for  various  kinds  of 
boards.  If  the  beating  operation  is  to  be  rendered  continuous  it 
is  more  likely  to  be  finally  accomplished  through  the  introduction 
of  refining  engines  similar  to  the  Jordan  and  Marshall  engines 
than  by  adding  attachments  to  ordinary  beaters.  However,  un¬ 
der  certain  conditions  such  appliances  as  the  one  described  above 
can  prove  very  useful. 

Claflin  Continuous  Beater. 

The  Claflin  engine  affords  a  means  of  making  the  beating 
operation  continuous,  which  is  an  advantage  from  many  points 
of  view.  At  the  same  time  the  Claflin  accomplishes  everything 
that  the  Jordan  engine  can  do.  Consequently  a  suitable  installa¬ 
tion  of  Claflin  engines  may  take  the  place  of  a  combination  of 


THE  BEATER  ROOM  267 

beaters  and  Jordans.  This  substitutes  one  type  of  machine  for 
two,  cuts  down  the  power  consumption  (since  the  Claflins  re¬ 
quire  less  power  than  Jordans)  and  at  the  same  time  affords  a 
continuous  process. 

Claflins  are  most  usually  installed  for  preparing  stock  requir¬ 
ing  severe  beating  treatment,  for  instance  kraft  stock  intended 
for  the  manufacture  of  high  grade  bag  and  wrapping  paper. 

The  construction  of  the  Claflin  engine  will  be  apparent  from 
the  illustrations.  The  cone  is  much  more  obtuse  than  in  the  Jor- 


Courtesy :  Claflin  Engineering  Co.,  Lancaster,  Ohio. 

Fig.  III. — Internal  view  of  shell  and  plug  of  Claflin  Continuous  Beater, 
showing  arrangement  of  knives  and  fillers. 

dan  engine,  which  accounts  for  the  lower  power  consumption. 
The  arrangement  of  the  knives  is  also  special  with  this  engine 
and  has  been  carefully  planned  so  as  to  yield  the  same  thorough 
brushing  out  of  the  fibres  obtained  in  ordinary  beating  engines 
when  operated  in  the  proper  manner. 

Power  for  Beater  Room. 

Proper  drive  for  the  equipment  of  the  beater  room  involves 
quite  a  problem  in  mechanical  engineering.  With  the  success 
of  the  resultant  sheet  of  paper  depending  directly  upon  correct 
pressure  and  duration  of  beating,  and  with  a  number  of  different 
gpdes  of  stock  being  carried  to  completion  in  a  number  of 
different  beating  and  Jordan  engines,  it  is  impossible  to  use  a 
centralized  power-plant.  The  conditions  are  quite  different  from 


268 


MODERN  PULP  AND  PAPER  MAKING 


those  in  a  factory  where  all  the  machines  are  driven  all  the  time 
and  are  all  shut  down  together  when  the  whistle  blows. 

In  the  beater  room  machines  are  shutting  down  and  starting 
at  all  hours  of  the  day  and  night,  and  with  a  central  source  of 
power,  a  great  deal  of  power  would  be  constantly  going  to  waste. 
The  best  procedure  is  to  install  a  large  electric  generating  plant 
and  then  drive  the  beaters,  Jordans,  agitators  in  stuff-chests, 
stuff -pumps,  etc,  by  individual  electric  motors. 

Maintenance  of  Beater  Room  Equipment. 

Beater  Roll:  The  beater  roll  is  made  up  of  a  number 
(generally  four),  of  cast-iron  discs  arranged  on  a  shaft.  Two  of 
these  discs  are  at  the  two  sides  of  the  roll  and  the  other  two 
are  near  the  center.  The  periphery  of  these  discs  is  slotted 
straight  across  at  stated  intervals  (usually  about  four  inches 
apart),  and  into  these  slots  the  knives  are  driven.  The  knives 
have  slots  in  each  end,  forming,  when  all  the  knives  are  in 
position,  a  complete  circle  of  slots,  one  on  each  side  of  the  roll. 
The  outside  discs  have  annular  grooves  located  in  a  line  with  the 
base  of  the  slots.  The  knives  are  driven  in  so  that  the  lugs 
on  the  knives  register  with  this  groove.  After  the  knives 
are  all  inserted  a  wrought  iron  ring,  which  fits  the  groove,  is 
heated  to  redness  and  driven  into  this  groove  and  allowed 
to  cool  and  shrink,  making  a  shrink  fit,  gripping  each  lug  of  the 
knives  on  both  ends  of  the  roll.  After  the  knives  are  thus  in¬ 
serted  and  fastened,  wooden  filling  pieces,  with  a  driving  fit,  are 
put  between  each  knife,  and  driven  home  by  placing  a  wooden 
driver  on  the  wooden  fillers  and  hitting  the  driver  with  a  sledge. 
Care  must  be  taken  to  insert  all  of  the  wood  fillers  and  to  tap 
them  down  gently  at  first  all  around  the  roll.  This  is  to  avoid 
tipping  the  knives,  and  to  bring  an  equal  strain  on  each  and 
every  knife. 

These  knives  (which  are  often  called  fly-bars  or  roll-bars), 
are  slightly  thicker  in  the  center  than  at  either  edge,  so  that 
the  swell  in  the  center  of  the  knife  helps  to  hold  the  wood 
filling  in  place,  since  the  wood  is  driven  in  beyond  the  swell. 
In  addition  to  this  the  knives  are  scored  slightly  so  that  the  wood 
when  it  becomes  swollen  with  water  fills  the  scorings.  All 
this  is  done  to  prevent  the  woods  from  coming  out  and  to 
hold  the  knives  in  an  upright  position. 

After  the  knives  are  inserted,  as  above  described,  it  will  be 
seen  that  no  matter  how  accurate  the  widths  of  these  knives  may 
be,  that  there  is  bound  to  be  a  slight  variation  in  their  height, 
making  an  uneven  periphery.  Thus  when  the  roll  is  let  down 
onto  the  bed-plate  there  will  be  found  to  be  one  or  two  high 
spots  on  the  cutting  surface  and  the  roll  will  strike  the  bed¬ 
plate  unevenly.  As  it  is  necessary  to  have  the  roll  run  absolutely 
smooth  when  resting  on  the  bed-plate,  the  roll  and  bed-plate  must 


THEi  BEATER  ROOM 


269 

be  ground  in  to  fit  and  produce  smooth  running.  When  the 
roll  is  on  the  bed-plate  and  in  proper  order  it  will  hum  as  it 
revolves  and  there  will  be  no  knocking  or  rasping  to  be  heard. 

Bandless  Beater  Rolls:  Several  manufacturers  of  beating 
engines  are  equipping  their  beaters  with  bandless  beater  rolls.  In 
these  rolls  the  knives  or  fly-bars  are  held  in  position  by  a  spe¬ 
cially  shaped  slot.  The  knives  are  so  made  that  the  section  in 
the  head  fits  the  dovetail  slots.  Between  the  heads  the  knives 
are  of  standard  section.  For  this  type  of  construction  the  fol¬ 
lowing  advantages  are  claimed:  To  fill  the  roll  it  is  not  necessary 
to  take  the  roll  out  of  the  lighters ;  new  bars  are  put  into  the 
slots  with  one  end  dovetail  lug  outside  and  next  to  an  outside 
head,  then  with  a  hammer  or  a  jack  the  bar  is  moved  endwise 
into  position.  The  wood  filling  is  then  put  in  and  the  roll  is 
ready  for  use.  However,  there  is  some  danger  of  the  knives 
becoming  rusted  and  stuck  in  the  slots  so  that  a  great  deal  of 
trouble  is  had  in  getting  them  out. 

Grinding  a  Roll  In:  To  grind  a  roll  in,  a  dam  is  erected 
of  boards  in  front  of  the  roll  and  in  the  space  between  this 
dam  and  the  backfall  water  and  sand  are  placed.  The  roll 
is  lowered  carefully  onto  the  bed-plate  and  allowed  to  revolve 
so  that  the  high  spots  will  just  touch  the  bed-plate.  The  roll 
is  lowered  as  fast  as  the  grinding  proceeds,  the  progress  of 
this  operation  being  judged  by  the  sound,  which  is  helped  . 
by  placing  a  smooth  stick  against  the  bed-plate  and  the  other 
end  against  the  ear.  This  makes  it  easy  to  tell  if  the  grinding 
is  going  on  in  a  satisfactory  manner.  When  this  grinding  process 
is  completed  the  roll  is  ready  for  use. 

In  running  the  beater  extreme  care  must  be  taken  that  no 
foreign  matter  gets  in  with  the  stock,  as  even  a  nail  would 
nick  the  knives  and  a  bolt  or  larger  object  would  seriously 
damage  the  knives  and  bed-plate. 

When  feeding  laps  the  roll  should  always  be  raised  from  the 
bed-plate,  about  an  inch,  to  avoid  jumping  the  roll  as  the  laps 
pass  through.  Laps  should  be  opened  out  before  being  placed 
in  the  beater,  as  this  makes  it  easier  for  them  to  pass  the  roll 
and  also  lessens  the  risk  of  foreign  substances  being  put  in  with 
the  laps.  Also  they  disintegrate  quicker. 

Beaters  intended  for  fresh  stuff  should  never  be  used  as 
broke  beaters.  The  broke  is  hard  to  disintegrate  and  also  is 
likely  to  contain  pieces  of  metal  such  as  bolts,  nuts,  tools,  etc. 

Beater  knives  should  be  inspected  carefully  to  see  if  acid 
contained  in  the  stock  is  wearing  them  thin.  Sometimes  beater 
knives  are  worn  to  a  knife  edge  in  this  manner,  under  which 
circumstances  they  should  be  replaced. 

In  the  course  of  time  beater  knives,  bed-plate  and  the  inside  of 
the  beater  itself  will  acquire  a  certain  smoothness  from  the  con¬ 
stant  polishing  of  the  circulating  stock.  It  is  very  valuable  to 
preserve  this  and  no  scraping  or  rough  handling  of  the  interior 


270  MODERN  PULP  AND  PAPER  MAKING 

of  the  beater  or  washing  with  strong  alkali  or  acid  should  be  per¬ 
mitted. 

Bed-Plate:  The  bed-plate  of  the  beater  consists  of  a  bank  of 
knives  and  wooden  fillers  arranged  alternately.  The  knives  and 
fillers  in  the  center  are  short  and  those  at  the  two  edges  are  longer, 
so  that  the  top  surface  of  the  bank  is  a  concave  trough  which  is 
parallel  to  the  bottom  of  the  beater  roll,  so  that  every  one  of  the 
knives  in  the  bed-plate  will  cut.  This  bank  is  fastened  together 
by  bolts  running  straight  through  and  fitted  with  nuts  counter¬ 
sunk  into  the  outside  pieces  of  wook.  Sometimes  instead  of  be¬ 
ing  set  parallel  with  the  roll-bars,  the  knives  are  set  at  an  angle 
so  as  to  deliver  a  shearing  cut  when  they  come  in  contact  with 
the  knives  of  the  beater  roll.  The  whole  bank  of  knives  and 
fillers  is  set  in  an  iron  trough  which  has  a  lip  perforated  with  a 
hole  at  its  outer  edge.  This  trough  is  set  right  across  the  path  of 
the  beater  roll,  its  outer  end  coinciding  with  an  opening  in  the 
shell  of  the  beater.  When  it  is  desired  to  repair  the  bed-plate  a 
bar  is  inserted  through  the  hole  in  the  lip  of  the  iron  trough  and  it 
is  drawn  right  out,  the  beater-roll,  of  course,  being  raised  during 
this  operation.  When  the  beater  bed-plate  knives  wear_  down, 
the  bed-plate  is  withdrawn  in  the  above  manner  and  shims  in¬ 
serted  under  the  bank  of  knives  and  fillers,  raising  it  the  required 
degree.  This  operation  can  be  repeated  until  the  knives  become 
worn  down  to  such  an  extent  that  it  is  necessary  to  renew  them. 

Jordan  Engine:  Generally  the  first  intimation  that  the  knives 
of  the  Jordan  plug  are  worn  down  appreciably,  is  the  falling  off 
in  delivery  of  the  stuff  through  the  engine,  owing  to  the  loss  of 
impelling  effect  on  the  stuff  on  account  of  the  knives  becoming 
flush  with  the  wooden  fillers.  Also,  the  whining  sound  charac¬ 
teristic  of  the  Jordan  when  the  knives  are  in  good  order  will  be 
reduced.  Also  there  is  a  characteristic  sensation  produced  when 
the  hand  is  placed  on  the  shell  of  a  Jordan,  the  knives  of  which 
are  cutting  properly,  which  is  not  met  with  in  a  Jordan,  the  knives 
of  which  are  worn  down.  This  can  easily  be  ascertained  by 
trial,  and  will  assist  materially  in  judging  of  the  necessity  for 
repair. 

When  the  delivery  of  the  Jordan  falls  below  requirements, 
the  plug  has  to  be  taken  out.  If  it  is  found  that  the  knives  are 
in  good  conditions  and  that  all  that  has  happened  is  that  the 
knives  are  worn  down  flush  with  the  wood  filling,  then  the  wooden 
filling  between  the  knives  can  be  chipped  out.  This  is  done  with 
a  chisel.  The  shell  of  the  Jordan  is  treated  in  the  same  manner 
as  the  plug.  One  chipping  is  all  that  a  Jordan  will  stand,  as  if 
this  operation  were  repeated  so  much  of  the  wooden  fillers  would 
be  removed  that  the  knives  would  not  have  adequate  support. 

Owing  to  the  acid  in  the  stock,  the  knives  will  gradually  wear 
very  thin,  and  quite  useless.  When  that  stage  is  reached  they 
must  be  replaced.  Also  they  must  be  replaced  if  they  have  be¬ 
come  hacked  or  nicked  by  foreign  matter  getting  into  the  Jordan. 


THE  BEATER  ROOM 


271 


Jordan  Outlets:  There  are  three  outlets  on  a  Jordan — bot¬ 
tom,  side  and  top.  The  outlets  are  situated  on  the  big  end.  They 
are  supplied  with  handhole  plates  when  not  in  use.  Only  one  at 
a  time  is  used.  Usually  the  top  outlet  is  the  one  used.  The 
lower  ones  would  be  used  in  the  event  of  making  free  stock  re¬ 
quiring  little  refining  in  the  Jordan.  The  use  of  the  upper  open¬ 
ing  backs  up  the  stock  in  the  Jordan,  holding  it  in  the  engine  for 
a  longer  time.  This  effect  can  be  increased  by  having  a  valve  on 
the  outlet  and  throttling  the  discharge.  If  the  plug  is  set  so  that 
the  knives  are  not  in  actual  contact  and  the  stock  is  throttled  so 
that  it  will  pass  through  the  engine  very  slowly  it  will^  be  found 
that  the  fibers  are  rubbed  against  each  other.  This  is  what  is 
called  stuffing  a  Jordon.  It  is  an  excellent  way  to  produce  a  long, 
strong  fibre,  such  as  is  noticed  in  strong  Kraft  paper.  When  the 
Jordan  is  stuffed,  it  will  be  noted  that  the  characteristic  whining 
persists  only  so  long  as  the  engine  is  full  of  stock.  If  the  stock 
is  allowed  to  run  out  the  whining  will  cease,  showing  that  the 
knives  are  not  actually  in  contact. 


SPECIFICATIONS  FOR  BEATING  ENGINE 

from 

(Name  of  Firm) 

(Address) 


Roll. 

Of  cast  iron,  .  diameter,  .  face ;  to  be  balance, 

and  the  inside  well  painted.  To  have  . heads  finished  to  an 

exact  diameter,  so  as  to  give  each  bar  a  solid  bearing  on  every 
accurately  fitting  slots  to  receive  the  bars  and  no  wedges  to  be  used  for 
supporting  or  holding  same  in  place.  Each  head  to  be  bored  a_  driving 
fit  and  firmly  keyed  to  the  cast  iron  shaft ;  the  outside  heads  finished  on 
their  outer  faces,  provided  with  suitable  “Banger  irons  ’  made  of  wrought 
iron  and  fastened  with  countersunk  head  machine  screws. 

Shaft. 

Of  cast  iron,  .  diameter  where  the  heads  are  located, 

finished  the  entire  length,  tapering  towards  the  ends;  provided  with  a 
finished  brass  cap  on  the  front  end.  Wrought  iron  collars  at  the  location 

of  the  back  side  and  midfeather,  and  a . collar  at  the  location 

of  the  front  side .  for  driving  cylinder  washers. 


Bearings. 

Front  . 

. . .  diameter,  .  . 

.  long ; 

back  . 

diameter,  . 

rounded. 

...  long.  Type, 

babbitted,  water 

jacketed.  Corners 

Fly  Bars. 

Of 

. .  in  "number. 

shoulder,  . 

.  back,  project- 

MODERN  PULP  AND  PAPER  MAKING 


272 

ing  .  beyond  the  filling,  planed  true  on  both  edges,  placed  in 

position  in  the  roll  and  securely  banded  with  .  wrought 

iron  bands  shrunk  on.  The  spaces  between  the  bars  to  be  filled  with  oak, 
carefully  fitted  and  securely  driven ;  then  the  ends  of  the  bars,  filling 
and  the  outer  faces  of  the  bands  are  to  be  finished  true  and  the  roll 
accurately  balanced. 

Pulley. 

Of  cast  iron, . diameter, . face„ . . bore, 

of  the  double  belt  type,  turned  with  a  suitable  crown  and  accurately 

balanced.  Placed . from  the  inside  of  the  tub.  Speed . 

R.  P.  M. 

Lighters. 

Of  cast  iron,  moulded  from  our  heavy  patterns,  with  steel  shafts  for 
operating  both  ends  of  the  rolls  simultaneously;  the  cross  shaft  passing 
above  the  tub.  The  posts  supported  by  the  harness  or  foundation,  the 

bases . square,  the  chaps  of . and  the  hand 

wheel  of . ;  the  hoist  of  the  worm  and  gear  type.  To  have 

a  quick  lever  relief  hoist. 

Bed  Plate. 

Elbow  style,  . wide,  . sheet  steel  cuts,  . 

outside  bars,  . hard  wood  filling,  planed  true  on  the  bottom 

and  firmly  keyed  into  the  plate  box  with  hard  wood  keys. 

Plate  Box. 

Of  cast  iron,  finished  all  over,  properly  fitted  to  the  bed,  projecting 
outside  of  the  tub  sufficiently  to  admit  of  easily  drawing  the  same. 

Tub. 

. long,  . wide  and  . deep  at 

center,  inside  dimensions;  side,  ends  and  midfeather  made  of . 

. ,  bottom  of  . ,  all  dressed  two 

sides,  jointed,  grooved  and  splined,  staves  hollowed  and  rounded.  The 
top  capped  with  a  cast  iron  rim  securely  screwed  to  the  woodwork  with 
countersunk  head  iron  screws ;  each  end  to  have  two  flat  wrought  iron 
bands.  The  planks  forming  the  bottom,  sides  and  midfeather  to  be 

securely  rodded  and  joint-bolted  together.  Back  side  supported  by . 

. heavy  cast  iron  braces ;  back  end,  front  side,  covered  with 

2"  Gulf  Cypress. 

Rub  Plates. 

Placed  on  the  front  side  and  midfeather,  extending  from  the  high 
point  of  the  backfall  to  the  extreme  front  of  the  roll,  from  the  top  of 
the  tub  down  to  the  bed,  set  into  the  woodwork  flush,  securely  fastened 

with  countersunk  head . *. . .  screws  and  made  of  . . 

. thick. 


Corners. 

Of  . . . . 

sides,  ends  and  midfeather  join  the  bottom. 


,  located  where  the 


THE  BEATER  ROOM 


273 


Protecting  Bands. 

Of  half  round  iron,  fastened  to  the  staves  with  countersunk 

head  iron  screws,  located  between  the  two  regular  flat  bands. 

Bed. 

To  have  patented  backfall;  the  bottom  made  of  . 

timber;  the  crown  of  . 

Plating. 

To  extend  from  the  extreme  high  point  of  the  backfall  to  the  back  side 
of  the  plate  box,  from  the  front  of  the  plate  box  to  the  low  point  of 
'the  apron  (where  there  is  an  apron)  otherwise  for  a  distance  of  18",  To 

be  of  . ,  . thick,  securely  fastened  to  the 

woodwork  with  countersunk  head  . screws. 

Curb. 

Heads  of  . ,  packing  boxes  of  . . 


cover  of  . .  fastened  to  the  heads  with 

round  headed  .  Of  our  patented  type. 


provided  with  adjustable  Oak  doctor,  cast  iron  deflector  and  protector. 

Spatter  Boards. 

Of  . .  made  in . pieces,  fastened 

together  with  heavy  strap  hinges  of  brass. 

Valves. 

Of  cast  brass;  .  emptying,  . wash-up. 

Hydrant  Valves. 

Of  cast  iron  and  brass;  . . 

Cylinder  Washers. 

. in  number,  shape . ,  diameter  . , 

face  .  Heads  of  .  buckets  of 

. ,  sash  of  . .  brass  wire 

cloth  . .  reinforced  by  3  mesh.  No.  18  cloth;  the 

edges  and  joints  protected  by  strips  of  sheet  brass,  all  fastened  to  the 
woodwork  by  copper  tacks.  The  discharging,  hoisting  and  driving  ap¬ 
paratus  complete,  of  cast  iron,  moulded  from  heavy  and  improved  pat¬ 
terns.  The  shafting  throughout  of  steel.  The  water-spout  supported 
independently  of  the  main  shaft;  the  water  box  fitted  to  receive  a  5"  cast 
iron  flanged  drain  pipe.  The  main  driving  gears  2^"  face,  Ya"  pitch. 

Patented  Emptying  Device. 

Consisting  of  an  invention  for  injecting  a  sheet  of  water  under  pres¬ 
sure  between  the  stock  and  the  bottom  of  the  tub,  thereby  not  only 
lessening  the  time  and  labor  required  for  dropping,  but  also  causing  the 
stock  and  water  to  become  more  thoroughly  mixed.  Located  in  the  back¬ 
fall  and  equipped  with  a  flanged  end,  iron  body,  bronzed  mounted,  single 
angle  gate  valve,  with  screws  stem  and  hand  wheel,  angle  end  to  turn 
down ;  you  furnishing  all  materials  and  doing  all  the  piping  for  connecting 
your  water  supply  to  the  above. 


274  MODERN  PULP  AND  PAPER  MAKING 

•  t 

Patented  Stock  Emptying  Valve. 

Consisting  of  an  oblong  rectangular  valve  and  its  cover,  usea  .n 
conjunction  with  our  patented  emptying  device,  of  iron  and  steel  through¬ 
out,  located  in  the  bottom  of  the  engine  and  in  front  of  the  roll,  ex¬ 
tending  between  the  front  side  and  the  midfeather,  being  so  placed  that 
its  top  is  flush  with  the  inside  of  the  bottom  of  the  engine.  The  lower 
end  having  a  machine  finished  flange,  the  total  depth  being  14"  from  the 
inside  of  the  tub.  The  shaft  operating  the  cover  projects  through  the 
front  side  of  the  engine,  is  supported  by  proper  bearings  and  has  an 
operating  lever  on  its  outer  end.  The  valve  seat  is  provided  with  an 
automatically  operated  shower  for  removing  the  stock  from  it  after 
emptying  and  before  lowering  the  cover,  we  furnishing  a  2"  iron  pipe 
extending  to  the  outside  of  the  beater  tub,  with  an  elbow,  nipple  and' 
a  2"  brass  plug  cock  valve.  When  the  cover  is  in  its  vertical  position  it 
becomes  a  dam,  retards  the  flow  of  the  stock  and  forces  it  down  the 
valve  opening,  which  latter  is  6". wide  and  of  a  length  nearly  equal  to 
the  face  of  the  roll. 

If  the  connecting  pipe  is  of  ample  size,  and  we  recommend  not  less 
than  18"  diameter  from  the  bottom  of  the  valve  to  the  chest  and  sloping 
sufficiently  so  that  the  stock  will  flow  freely,  then  the  engine  can  be 
emptied  almost  instantly  without  using  a  rake  and  with  no  labor  other 
than  opening  the  water  gate  valve  and  raising  the  cover  of  the  emptying 
valve  to  its  vertical  position. 

Floor  Plates. 

Of  cast  iron  throughout,  for  the  support  of  the  lighter  posts,  one 
single  plate  being  required  for  each  pair  of  posts,  the  raised  surfaces  at 
the  ends  for  the  support  of  the  posts  being  machine  finished,  the  inter¬ 
vening  space  between  these  raised  surfaces  having  a  drip  pan  bottom  and 
ribbed  edges,  the  bottom  slanting  to  a  2"  drain  hole  located  at  the  center ; 
we  to  furnish  the  tap  bolts,  drill  and  tap  the  holes  for  fastening  the 
posts  to  the  plates,  you  to  set  the  plates,  furnish  and  install  the  bolts  for 
fastening  them  to  the  floor  system. 

Stock  Guides. 

Of  cast  iron,  fastened  with  brass  screws  to  the  midfeather  and  front 
side  on  the  inside  of  the  engine  directly  in  front  of  the  roll,  for  the 
purpose  of  guiding  the  stock  away  from  the  midfeather  and  front  side. 

Piping. 

All  piping  of  every  name  or  nature  not  specified  as  being  furnished 
by  ‘us  is  to  be  furnished  and  installed  by  the  Purchaser. 

Finish. 

The  woodwork  throughout  thoroughly . 


outside,  . inside,  with . 

coats  of  pure .  The  iron  work  to  have 


. .  .coats  of  pure  lead  paint  and  oil  on  all  unfinished  exposed 

parts.  Machined  parts  well  slushed  before  shipment. 

Workmanship  and  Material. 

All  workmanship  first-class  in  every  respect  and  materials  of  the  best 
of  their  several  kinds  for  the  purposes  intended. 

Note. 

The  assembling  and  erecting  of  the  tub  and  of  the  parts  which  attach 
thereto  is  to  be  done  at  the  Purchaser’s  mill  rather  than  at  our  shops. 


THE  BEATER  ROOM 


275 


The  various  parts  of  the  complete  engines  are  to  be  shipped  in  as 
much  of  a  knocked-down  condition  as  in  our  judgment  may  be  best. 

Conditions. 

The  date  agreed  upon  for  the  shipment  of  this  machinery  is  made 
in  good  faith ;  it  is  contingent,  however,  upon  the  non-occurrence  of 
strikes,  accidents  and  other  delays  unavoidable  or  beyond  our  control. 

Title  of  Machinery. 

The  title  to  this  machinery  shall  not  vest  in  the  purchaser  until  it  is 
fully  paid  for;  the  fact  that  said  machinery  may  attach  to  realty  by 
any  means  whatever,  shall  not  be  considered  as  making  it  a  part  of  such 
realty,  but  till  fully  paid  for,  the  same  shall  be  and  remain  personal 
property  and  the  purchaser  agrees  to  execute  or  cause  to  be  executed, 
acknowledged  and  delivered  to  us,  all  legal  instruments  necessary  and 
appropriate  to  preserve  our  title  therein.  If  a  note  or  notes  of  the  vendee 
or  any  other  person  is  or  are  accepted,  the  title  to  said  machinery  shall 
not  pass  from  us  until  such  note  or  notes,  all  extensions  and  renewals 
thereof  and  interest  thereon,  shall  have  been  paid  in  full,  and  if  default 
is  made  in  payment  of  the  contract  price  of  said  machinery,  whether 
evidenced  by  note  or  otherwise,  the  right  is  expressly  reserved  and  given 
to  us  to  enter  the  premises  where  said  machinery  may  be,  and  rernove 
the  same  as  our  property.  The  taking  of  security  other  than  provided 
for  shall  not  operate  as  a  waiver  of  our  statutory  lien,  and  consent  is 
given,  that  we  may,  without  notice,  accept  security  and  thereafter  increase, 
diminish,  exchange  or  release  the  same. 

Acceptance, 

Where  the  payments  are  contingent  upon  the  dates  specified  in  the 
contract  for  shipment,  completion  of  erection  or  starting  of  the  ma¬ 
chinery,  and  should  it  be  impossible  or  impracticable  to  ship,  erect  and 
start  said  machinery  on  these  dates,  owing  to  conditions  oyer  which  we 
have  no  control,  then  shall  this  machinery  and  work  be  accepted  and 
paid  for  as  agreed  in  the  contract,  all  providing  that  we  are  ready  to 
ship,  erect  and  start  machinery  on  these  dates,  the  payments  being  de¬ 
ferred  or  extended  only  by  the  additional  time  that  we  require  to  fulfill 
our  contract. 

Safe  Keeping. 

The  purchaser  shall  become  responsible  for  the  safe  keeping  of  this 
machinery  and  shall  insure  same  for  our  benefit,  as  our  interest  may 
appear  from  the  time  it  shall  be  shipped  from  our  works. 

Agreements. 

There  are  no  understandings  or  agreements  not  expressed  herein  and 
nothing  is  included  that  is  not  particularly  mentioned. 

Payments. 

The  contract  price  of  any  unpaid  part  thereof,  shall  draw  interest 
after  due,  at  a  legal  rate  until  paid,  and  when  the  time  of  payments 
extends  beyond  thirty  days,  such  deferred  payments  shall  be  evidenced 
by  a  negotiable  note  or  notes  at  our  option. 

Erection. 

We  will  deliver  F.  O.  B.  cars . 


.  (Address) . . 

you  to  unload  same  from  cars  and  place  in  Engine  Room  of  your  mill, 
after  which  we  will  send.;...’ . competent . to . . 


276  MODERN  PULP  AND  PAPER  MAKING 

the .  It  is  agreed  that  all  labor  and  materials  relative 

to  the  harness,  floor  system,  leaders  or  pipes  of  any  kind,  pulley  curbs, 
belts,  grinding  of  rolls,  holding-down  bolts  or  any  other  kind  of  labor 
and  materials  which  do  not  strictly  belong  to  the  engines,  is  not  a  part 
of  this  contract  and  is  to  be  done  and  furnished  by  you,  without  expense 

to  us.  Price  per  day  of  ten  hours  for  the  Superintendent.  . .  ._ . .  .., 

for  additional  mechanics  .  The  charge  to  include  time 

occupied  going  to  and  returning  from  your  mill  as  well  as  while  there. 
You  are  to  pay  all  traveling  expenses,  board,  lodging  and  transportation 
of  tools  both  ways,  also  furnish  all  millwrights  and  laborers  (without 
expense  to  us)  that  our  superintendment  may  deem  necessary  in  order 
to  erect  the  machinery  with  the  least  possible  delay. 


JORDAN  ENGINE  SPECIFICATIONS 
•  from 

(Name  of  Firm) 

(Address) 

Type .  Speed .  Weight . 

R.  P.  M . lbs. 

Dimensions  Over  All.  Height  to  Center  of  Sh.aft. 

i4'-io3/8"x3'9"  2'-6" 


Plug. 

Of  cast  iron,  long;  2'-ioJ4"  and  i'-8"  diameters,  respectively,  at 

the  large  and  small  ends,  over  bars.  To  consist  of  a  taper  shell,  moulded 
from  a  heavy  pattern,  tbe  center  bored  out  and  provided  with  a  hub  at 
each  end.  The  casting  to  be  trued  up  from  the  inside  and  machined  to 
proper  dimensions  on  its  outer  face ;  the  hubs  bored,  splined  and  firmly 
keyed  to  the  shaft  by  fitted  taper  keys,  the  latter  being  forced  into  position 
by  hydraulic  pressure.  To  have  five  (5)  raised  surfaces  with  finished 
slots  to  receive  the  bars.  To  be  balanced. 

Shaft. 

Of  hammered  iron,  turned  all  over  true  to  sizes;  4  15/16"  diameter  at 
the  pulley  fit  and  bearings,  bossed  at  the  locations  of  the  sleeves  and  plug. 
To  have  standard  splines,  provided  with  machine-finished  keys  for  fasten¬ 
ing  the  pulley  and  plug  in  position.  At  the  back  bearing  there  are  to  be 
five  (5)  taper  grooves  to  take  the  end  thrust. 

Sleeves. 

Two  (2)  in  number,  of  seamless  brass  tubing,  YA  thick,  shrunk  on 
the  shaft  at  the  location  of  the  packing  boxes,  extending  from  the  ends 
of  the  plug  to  the  nearest  bearings  and  finished  on  their  outer  surfaces. 

Plug  Bars. 

. in  number,  of  Open  Hearth  Jordan  Steel;  2  11/16"  wide, 

. ,  S'^Ya"  long,  . thick,  . .  28"  long, 

. thick,  planed  to  a  width,  placed  in  position  in  the  plug  and 

securely  banded  with  five  (s),  Yi^Vi"  wrought  iron  bands  shrunk  on. 


THE  BEATER  ROOM 


277 


The  spaces  between  the  bars  to  be  filled  to  the  proper  height  with  dry  Oak, 
carefully  fitted  and  well  driven.  The  plug  then  to  be  accurately  balanced. 

Shell. 

Moulded  from  heavy  patterns,  of  cast  iron,  bored  to  a  true  taper  inside 
and  the  ends  squared  up ;  the  heads  counter-bored  to  fit,  drilled  to  inter¬ 
changeable  templates  and  fastened  in  position  with  standard  tap  bolts. 
To  have  four  (4)  wrought  iron  guide  bars  of  i"x^"  iron,  bent  to  proper 
shape,  placed  quartering  and  lengthwise  and  cap-screwed  to  the  inner 
surface.  To  be  provided  with  packing  boxes  and  glands  where  the  shaft 
passes  through  the  heads;  these  to  be  finished  in  the  usual  manner.  To 
have  two  (2)  supporting  brackets  each  side.  The  small  end  projecting 
beyond  the  plug  about  14",  having  an  8"  inlet  at  the  top,  a  hand  hole  with 
cover  on  one  side  and  a  sand  trap  with  clean-out  hole  and  cover  at  the 
bottom.  The  outlets  to  be  6"  in  diameter  and  four  (4)  in  number,  three 
(3)  to  have  plain  caps  and  the  fourth  a  6"  wrought  iron  pipe  flange  with 
standard  thread. 

Shell  Bars. 

Of  Open  Hearth  Jordan  Steel ;  type,  .  in  number, 

i6j4"  long,  wide . thick,  planed  to  a  width,  placed  in 

position  in  the  shell,  filled  in  between  to  the  proper  height  with  dry  Oak, 
carefully  fitted,  each  section  being  securely  keyed.  The  filling  to  be  made 
with  two  (2)  chippings. 

End  Adjustment. 

To  be  made  in  the  usual  manner  by  a  hand  wheel,  screw  and  nut;  the 
latter  being  fastened  to  the  under-side  of  the  back  bearing. 

Pulley. 

Diameter . ,  face  18 j4".  Of  cast  iron,  split,  of  the  double 

belt  type,  turned  with  a  suitable  crown,  accurately  bored,  keywayed  and 
balanced.  To  have  two  (2)  set  screws  on  top  of  the  key;  the  latter  to  be 
of  standard  size  and  straight. 

Bearings. 

Three  (3)  in  number,  length  15",  of  the  ring  oiling,  water-jacketed 
type,  with  slush  cups  and  vertical  adjustment;  oil  rings  of  composition, 
finished  all  over.  The  bases  and  sides  machined  and  babbitted ;  one  being 
fitted  to  the  shaft  grooves. 

Guides. 

Two  (2)  in  number,  of  cast  iron,  fastened  to  the  two  (2)  heads  of 
the  shell;  the  inner  surfaces  to  be  machine  finished. 

Stands. 

Five  (s)  in  number,  of  cast  iron,  two  (2)  each  for  the  support  of  the 
guides  and  shell  and  one  for  the  out-board  bearing;  all  of  the  box  type 
with  machine-finished  tops  and  feet,  fastened  to  the  base  by  tap  bolts; 
the  tops  provided  with  clamping  and  tap  bolts. 

Base. 

Of  cast  iron,  moulded  from  a  heavy  pattern,  thoroughlv  braced  and 
cross-ribbed,  provided  with  a  solid  top  except  where  the  pulley  is  located, 
sloping  to  a  drain  outlet  at  the  back  end,  which  is  equipped  for  a  2" 
standard  pipe  flange.  To  have  pockets  on  the  ends,  so  that  bars  may  be 
used  for  moving  the  engine,  also,  eight  (8),  54"  anchor  bolt  holes.  Both 
the  top  and  bottom  to  be  accurately  planed. 


278  MODERN  PULP  AND  PAPER  MAKING 

Sand  Box. 

Of  cast  iron,  of  neat  design,  placed  on  top  of  and  fastened  to  the 
shell  at  the  feed  end,  provided  with  an  8"  inlet  and  discharge  and  a 
cross  partition  or  dam,  dividing  it  into  two  (2)  chambers ;  the  first  having 
a  clean-out  hole  and  cover  on  the  side.  To  have  a  6"  vent  pipe,  30'  in 
length,  equipped  with  a  cast  iron  cap. 

End  Adjustment. 

Made  in  the  usual  manner  by  a  hand  wheel,  screw  and  nut;  the  latter 
being  fastened  to  the  under-side  of  the  back  bearing  and  the  screw  being 
connected  through  a  train  of  machine  dressed  spur  gearing,  a  shaft 
running  lengthwise  of  the  Jordan,  supported  by  bearings  attached  to  the 
base,  the  outer  end  being  threaded  and  engaging  a  nut  fastened  to  the 
bottom  of  the  motor  base,  so  that  the  same  end  motion  which  is  given 
by  the  adjusting  screw  to  the  plug  is  also  transmitted  through  the  spur 
gearing,  shaft  and  nut  to  the  motor  frame. 

Couplings. 

Of  the  flexible  insulated  type,  one-half  . . . ,  bored,  fitted 

keywayed  and  keyed  to  the  end  of  the  plug  shaft;  the  other  half  whole, 
bored  and  keywayed  to  dimensions  to  be  furnished  by  the  Purchaser, 
we  to  furnish  the  key. 

Motor. 

Furnished  by  the  Purchaser  without  expense  to  us  and  without  pulley, 
outboard  bearings  or  sub-base.  The  end  of  the  shaft  next  to  the  Jordan 
Plug  to  project  sufficiently  to  receive  a  one-half  coupling;  to  be  provided 
with  a  coupling  fit  and  keyway.  The  base  to  have  two  planed  surfaces  in 
place  of  four;  each  of  sufficient  length  and  width  to  support  the  motor 
and  to  comply  with  our  requirements.  These  to  be  finished  on  the  bottom, 
outer  edges  and  the  ends.  Holes  to  be  drilled  and  tapped  in  the  outer 
edges  an  the  ends  to  receive  YA  tap  bolts,  to  which  will  be  attached 
castings  which  we  will  furnish.  On  the  bottom  of  the  frame  there  must 
be  a  raised  flat  surface,  size  about  5"x8" ;  to  be  planed,  to  have  a  counter¬ 
bore  in  the  center  YA"  diameter,  YA  deep,  to  have  four  YA  holes  drilled 
and  tapped  to  receive  four  tap  bolts  which,  in  turn,  will  fasten  a  nut  to 
the  frame.  We  wilf  furnish  the  castings,  the  nut  and  all  tap  belts  above 
referred  to,  but  they  will  be  attached  to  the  motor  base  and  frame  by 
the  Purchaser  at  his  Mill. 

This  proposal  is  made  with  the  understanding  that  the  motor  purchased 

will  not  be  higher  than  .  from  the  base  to  the  center  of  the 

shaft,  that  the  width  from  out  to  out  of  the  feet  will  not  exceed 

. ;  otherwise  an  extra  charge  will  be  made  and  the  amount 

of  same  will  depend  upon  the  increased  dunebsuibs  if  the  motor  is  over 
and  above  those  specified. 

Jordan  Base. 

Of  cast  iron,  moulded  from  a  heavy  pattern,  thoroughly  braced,  and 
provided  with  a  solid  top  sloping  to  a  drain  outlet  at  the  back  end,  which 
is  tapped  for  a  standard  pipe.  Top  where  the  stands  are  located,  the 
bottom  and  the  ends  to  be  accurately  planed,  one  of  the  latter  being  drilled 
and  provided  with  bolts  for  fastening  it  to  the  motor  base. 

Motor  Base. 

Of  cast  iron,  moulded  from  a  heavy  pattern,  thoroughly  braced,  and 
provided  with  a  solid  top.  Top  and  bottom  as  well  as  one  end  to  be 


THE  BEATER  ROOM 


279 


accurately  planed,  the  latter  Ueing  drilled  to  receive  the  bolts  which  clamp 
it  to  the  Jordan  base.  To  be  provided  with  our  special  arrangements  for 
the  support  of  the  motor  and  easy  adjustment  thereof. 

Notice, 

The  purchaser  must  advise  the  manufacturer  of  the  motor  and  before 
contracting  for  same,  in  reference  to  all  the  special  arrangements  required 
and  as  outlined  above. 

Conditions. 

The  date  agreed  upon  for  the  shipment  of  this  machinery  is  made  in 
good  faith ;  it  is  contingent,  however,  upon  the  non-occurrence  of  strikes, 
accidents  and  other  delays  unavoidable  or  beyond  our  control. 

Title  of  Machinery, 

The  title  to  this  machinery  shall  not  vest  in  the  purchaser  until  it  is 
fully  paid  for ;  the  fact  that  said  machinery  may  attach  to  realty  by  any 
means  whatever,  shall  not  be  considered  as  making  it  a  part  of  such 
reality,  but  till  fully  paid  for,  the  same  shall  be  and  remain  personal 
property  and  the  purchaser  agrees  to  execute  or  cause  to  be  executed, 
acknowledged  and  delivered  to  us,  all  legal  instruments  necessary  and 
appropriate  to  preserve  our  title  therein.  If  a  note  or  notes  of  the  vendee 
or  any  other  person  is  or  are  accepted,  the  title  to  said  machinery  shall 
not  pass  from  us  until  such  note  or  notes,  all  extensions  and  renewals 
thereof  and  interest  thereon,  shall  have  been  paid  in  full,  and  if  default 
is  made  in  payment  of  the  contract  price  of  said  machinery,  whether 
evidenced  by  note  or  otherwise,  the  right  is  expressly  reserved  and  given 
to  us  to  enter  the  premises  where  said  machinery  may  be,  and  remove  the 
same  as  our  property.  The  taking  of  security  other  than  provided  for 
shall  not  operate  as  a  waiver  of  our  statutory  lien,  and  consent  is  given, 
that  we  may,  without  notice,  accept  security  and  thereafter  increase, 
diminish,  exchange  or  release  the  same. 

Acceptance. 

Where  the  payments  are  contingent  upon  the  dates  specified  in  the 
contract  for  shipment,  completion  of  erection  or  starting  of  the  machinery, 
and  should  it  be  possible  or  impracticable  to  ship,  erect  and  start  said 
machinery  on  these  dates,  owing  to  conditions  over  which  we  have  no 
control,  then  shall  this  machinery  and  work  be  accepted  and  paid  for  as 
agreed  in  the  contract,  all  providing  that  we  are  ready  to  ship,  erect  and 
start  machinery  on  these  dates,  the  payments  being  deferred  or  extended 
only  by  the  additional  time  that  we  require  to  fulfill  our  contract. 

Safe  Keeping. 

The  purchaser  shall  become  responsible  for  the  safe  keeping  of  this 
machinery  and  shall  insure  same  for  our  benefit,  as  our  interest  may 
appear  from  the  time  it  shall  be  shipped  from  our  works. 

Agreements. 

There  are  no  understandings  or  agreements  not  expressed  herein  and 
nothing  is  included  that  is  not  particularly  mentioned. 

Payments. 

The  contract  price  of  any  unpaid  part  thereof,  shall  draw  interest  after 
due,  at  a  legal  rate  until  paid,  and  when  the  time  of  payments  extends 
beyond  thirty  days,  such  deferred  payments  shall  be  evidenced  by  a 
negotiable  note  or  notes  at  our  option. 


28o  modern  pulp  and  PAPER  MAKING 

Finish. 

To  be  assembled  in  our  shops  and  shipped  whole.  To  have  three  (3) 
coats  of  pure  lead  paint  and  oil  on  all  unfinished,  exposed  parts ; 
machined  parts  well  slushed  before  shipment. 

Workmanship  and  Materials. 

All  joints  machine-dressed  and  bolt  holes  drilled.  _  Workmanship 
first-class  in  every  respect  and  materials  the  best  of  their  several  kinds 
for  the  purposes  intended. 


XIII.  The  Machine  Room. 


The  Machine  Room  is  the  name  commonly  given  to  the  build¬ 
ing  housing  the  paper  making  machines  together  with  the  equip¬ 
ment  for  driving  them  and  for  supplying  stock  to  the  machines 
and  steam  to  the  drying  equipment. 

The  machine  ordinarily  used  for  making  paper  is  the  Four- 
drinier  machine,  and  all  remarks  regarding  paper  machines  in  the 
subsequent  paragraphs  refer  to  that  machine  in  its  usual  form. 

Although  there  are  numerous  firms  manufacturing  Four- 


drinier  machines  of  excellent  design  and  construction,  and  al¬ 
though  each  of  these  firms  has  introduced  certain  special  features 
which  they  think  tend  towards  efficiency  and  perfection,  yet  the 
general  principles  are  the  same —  i.  e.,  the  same  essential  parts 
are  found  in  all  the  different  makes — and  the  descriptions  in  this 
chapter  will  apply  to  any  make  of  machine.  Paper  machines  are 
not  built  standard  and  carried  in  stock  like  grinders  or  beaters. 
They  are  designed  and  built  special  for  each  case  in  accordance 
with  specifications  drawn  up  by  the  buyer,  models  for  which 
will  be  found  at  the  end  of  this  chapter.  Other  maclfines  some¬ 
times  used  for  paper  making  are  the  Harper  Fourdrinier,  the 
Cylinder  Machine,  the  Flying  Dutchman,  Yankee  Machine,  etc. 
These  forms  of  machine  will  be  dealt  with  later  on. 

281 


282  MODERN  PULP  AND  PAPER  MAKING 

The  Fourdrinier  machine  consists  essentially  of  a  device  for 
allowing  carefully  screened  pulp  of  constant  consistency  to  flovv 
onto  a  horizontal  wire  screen,  made  in  the  form  of  an  endless 
belt  and  travelling  constantly  awa^  from  the  point  where  the  pulp 
flows  on  it.  The  water  in  the  pulp  drains  through  the  wire,  this 
drainage  being  assisted  by  suction  boxes  applied  under  the  wire 
at  certain  points.  At  the  end  of  the  wire  farthest  from  the  point 
where  the  pulp  flows  on  it,  is  a  pair  of  rolls  between  which  the 
film  of  fibres  from  the  wire  passes.  At  this  point  the  film  of 
fibres  still  contains  much  moisture,  so  it  is  passed  through  other 
felt  covered  rolls,  which  press  more  water  out  of  it._  Next  it 
passes  through  a  long  series  of  steamheated  iron  cylinders,  al 
ways  supported  by  a  layer  of  felt  which  travels  with  the  papei, 
and  these  cylinders  drive  out  all  the  remaining  water  except  a 
small  percentage  always  present  even  in  paper  commonly  con¬ 
sidered  quite  dry.  Finally  the  paper  passes  through  polished 
calender  rolls  to  give  it  a  *Tnish  and  onto  reels  where  it  is 
wound  up. 

The  foregoing  description  gives  little  idea  of  what  a  complex 
and  intricate  mechanism  a  Fourdrinier  machine  is,  and  of  the 
necessity  of  having  every  part  in  perfect  running  order,  and  per¬ 
fectly  adjusted  to  every  other  part  if  satisfactory  work  is  to  be 
done. 

Before  reading  the  subsequent  sections  of  this  chapter,  in 
which  it  will  be  attempted  to  outline  the  practical  details  of  Four¬ 
drinier  machine  operation,  the  reader  is  urged  to  study  carefully 
the  accompanying  diagram  of  the  Fourdrinier  machine,  learning 
carefully  the  name  and  location  of  all  the  various  parts.  After 
studying  this  diagram  it  would  be  highly  advantageous,  if  oppor¬ 
tunity  presents,  to  study  a  machine  in  actual  operation,  identify¬ 
ing  the  various  parts  of  the  machine  and  carefully  noting  their 
functions. 

Screens. 

Before  being  allowed  to  flow  onto  the  wire  of  the  machine 
the  stock  is  given  a  final  screening,  through  screens  much  finer 
than  any  previously  employed,  in  order  to  remove  every  possible 
trace  of  dirt,  slivers,  etc. 

The  screens  (which  in  Europe  are  frequently  called  “strain¬ 
ers”),  commonly  used  for  this  purpose  are  flat  diaphragm  screens 
(although  rotary  and  other  types  of  screens  are  sometimes  pre¬ 
ferred),  the  screening  surface  of  which  consists  of  a  number 
(usually  12)  of  flat  metal  plates  perforated  with  slits.  These 
plates  form  the  top  of  a  shallow  box,  tray  or  vat,  the  bottom  of 
which  is  made  up  of  diaphragms  which  serve  to  suck  the  stock 
through  the  screens.  These  diaphragms  are  actuated  by  devices 
known  in  papermakers’  lingo  as  “trotters.”  These  trotters  are 
simply  arms  attached  to  the  under  side  of  each  diaphragm  and 
hearing  at  their  lower  extremity  a  toe-block,  usually  of  maple. 


THE  MACHINE  ROOM  283 

\yhich  rides  on  a  cam  having  three  or  four  drops  to  the  revolu¬ 
tion.  The  cams  are  mounted  on  a  shaft  making  about  125  revolu¬ 
tions  per  minute  and  are  arranged  so  the  diaphragms  are  not 
in  step,  i.  e.,^  so  one  is  up  when  the  others  are  down  or  in  inter¬ 
mediate  positions  (like  pistons  in  a  four  cylinder  automobile 
engine).  The  toe-blocks  are  removable,  as  they  wear  out  and 
have  to  be  replaced.  The  diaphragms  are  attached  to  the  frame 
of  the  screen  by  means  of  a  leather  or  rubber  flap  which  is 


Courtesy :  Sandy  Hill  Iron  S'  Brass  Works,  Hudson  Falls,  N.  Y. 

FiS-  1 13- — Diaphragm  screen,  as  used  in  connection  with  Fourdrinier  paper 

machine. 


sufficiently  flexible  to  permit  of  the  up  and  down  motion  of  the 
diaphragm,  and  at  the  same  time  affords  a  tight  joint. 

The  size  of  the  screen  is  such  that  it  takes  regular  size  plates 
12  in.  by  43  in.  The  .screen  is  so  arranged  as  to  have  sufficient 
outlet  for  its  capacity.  The  size  of  the  slots  in  the  plate  is  gov¬ 
erned  by  the  kind  of  paper  being  made,  ranging  anywhere  from 
8  to  18/1000  of  an  inch  in  width.  Paper  containing  a  large  per¬ 
centage  of  sulphite,  Kraft  or  any  long-fibered  stock  will  naturally 
require  a  screen  having  larger  slots  than  paper  made  from  a 
shorter-fibered  stock.  Sometimes  the  screens  contain  two  differ¬ 
ent  sizes  of  slots. 

For  instance,  if  a  slot  12  or  14/1000  is  a  little  too  small  to  pass 
the  paper  stock,  three  or  four  plates  may  be  taken  out  and  re¬ 
placed  by  16  cut  plates,  for  instance,  at  the  upper  end  of  the 


284 


MODERN  PULP  AND  PAPER  MAKING 

screen  where  the  stock  enters  the  screen  through  a  large  pipe  or 
flow-spout.  This  pipe  is  usually  equipped  with  a  quick  opening 
valve  so  each  screen  can  be  operated  exactly  according  to  its  ca¬ 
pacity.  The  stuff  goes  into  the  upper  end  of  the  screen  and  flows 
toward  the  opposite  end  and  the  rapid  action  of  the  pulp  when  it 


Fig.  113a. — Diagram  showing  side  and  end  elevations  of  typical  diaphragm 

screen. 


strikes  the  screen  does  not  permit  of  the  stuff  standing  on  the 
16-cut  plates.  However,  a  good  portion  goes  through,  but  dirt 
and  shieves  will  not  go  through  on  account  of  the  rapid  stirring 
and  agitation,  so  that  the  16-cut  plates  help  deliver  the  stock 
through  without  in  the  least  increasing  the  dirt  or  shieves  m  the 
paper. 


THE  MACHINE  ROOM 


285 

It  is  sometimes  advisable  to  dam  up  the  stock  as  it  flows  onto 
the  surface  of  the  screen  plates  by  putting  in  cleats  running 
crosswise  of  the  screen,  thus  compelling  the  current  as  it  flows 
over  the  dam,  to  zig-zag  and  retard.  In  these  cases  it  is  arranged 
to  have  the  fine  plates  at  the  dry  end  of  the  screw,  or  zig-zag 
path,  so  that  the  large  particles  of  dirt  and  shieves  are  carried 
forward  with  the  flow  of  the  stock  and  finally  come  to  rest  at  the 
dry  end.  If  these  plates  were  coarse  the  dirt  and  shieves  would 
finally  jar  through  and  get  into  the  paper. 

The  screen  is  also  equipped  with  adjustable  dams  at  the  out¬ 
let,  so  that  the  water  and  stock  can  be  backed  up  under  the 
plate  at  the  desired  distance  from  the  plate.  There  is  a  point 
that  is  just  right,  which  can  be  determined  by  experimenting  a 
little  with  the  dams.  If  the  stock  under  the  plates  is  kept  at  too 
high  a  level,  i.  e.,  too  near  the  plates,  the  oscillation  of  the  dia- 


Courtesy:  Union  Screen  Plate  Co.,  Fitchburg,  Mass. 


Fig.  1 14. — Three  types  of  plate  used  in  diaphragm  screens. 


phragm  will  cause  the  stock  to  back  up  through  the  plates.  More¬ 
over,  the  long  fibered  stock  might  weave  into  cobweb-like  particles. 
The  slots  in  the  screen  plates  are  quite  large  on  the  bottom  side 
and  V-shaped,  thus  furnishing  large  grooves  into  which  the  stock 
would  be  continually  beaten  by  the  up-and-down  motion  of  the 
diaphragm,  and  thus  the  process  of  weaving,  alluded  to  above, 
set  up.  The  cobweb-like  accretions  would  finally  get  so  large  and 
heavy  that  they  would  drop  off  and  float  out  through  the  screen 
outlet  onto  the  wire.  These  larger  particles  are  almost  sure  to 
break  the  paper  down  on  the  wire,  but  if  any  of  the  smaller  of 
them  do  pass,  they  make  a  large  blotch  in  the  paper,  which  is 
usually  wet  and  spoils  that  portion  of  the  sheet.  Consequently, 
great  care  must  be  exercised  in  adjusting  the  dams  and  thus  reg¬ 
ulating  the  height  of  the  stock  under  the  screen  plates, 

A  good  way  to  decide  the  adjustment  of  the  dams  when  the 
screens  are  in  use  is  to  stand  up  above  the  screens  and  watch 
their  operation,  gradually  and  carefully  lowering  or  raising  the 
dam  as  may  be  required.  Care  must  be  taken  during  this  adjust¬ 
ment  not  to  flood  the  wire  when  lowering  the  dam,  or  to  cause 
any  considerable  removal  of  stock  when  raising  the  dam.  Either 
of  these  courses  would  result  in  breaks  in  the  paper.  If  the 
lowering  or  raising  is  done  %.  inch  or  less  at  a  time  the  adjust¬ 
ment  can  be  made  and  the  proper  height  of  the  dam  arrived  at 
without  stopping  operations  and  without  any  injury  to  the  paper 
that  is  being  made. 

Screen  plates  should  never  be  walked  on,  especially  with  hob- 


286  MODERN  PULP  AND  PAPER  MAKING 

nailed  shoes,  as  the  bars  will  become  bent,  thus  opening  the  slots 
to  an  inordinate  width,  for  instance,  a  slot  intended  to  be  14/1000 
of  an  inch  will  become  possibly  24/1000  and  will  then  let  through 
coarse  shieves  and  dirt. 

If  it  is  necessary  to  walk  on  the  plates  at  all  it  should  be  done 
by  stepping  on  tbe  toes  and  soles  of  the  shoes  and  not  allowing 
the  heels  to  touch,  but  it  is  much  preferable  that  the  plates  be  not 
walked  on  at  all. 

When  the  slots  in  the  screen  plates  become  filled  with  stock, 
the  best  way  to  clean  them  is  to  draw  them  out  separately  with  a 
tool  furnished  by  tbe  screen  plate  makers,  which  is  just  small 
enough  to  go  into  the  slot  and  pull  out  the  fibres  that  have  been 
caught  in  the  slots  and  thus  plug  them  up. 

Some  mills  allow  the  machine  help  to  use  a  wide,  thin  piece 
of  rubber  belting  nailed  to  a  handle,  with  which  they  clear  the 
slots  by  pounding  the  belt  on  top  of  the  plates.  If  this  is  al¬ 
lowed,  great  care  should  be  exercised.  Some  predetermined 
tbickness  and  weight  of  this  slapper  should  be  decided  upon  and 
the  job  should  be  entrusted  to  a  careful  workman.  Otherwise 
the  bars  of  the  screen  plate  are  sure  to  become  bent  just  as  if  they 
had  been  walked  on  or  bent  in  some  other  way. 

The  screens  should  be  taken  up  and  washed  thoroughly  as 
often  as  is  necessary.  It  is  usually  customary  to  wash  the  screens 
once  a  week  by  rinsing  and  scrubbing  off  all  the  slime  that  may 
have  accumulated  under  the  vats  during  the  week.  If  the  slime  is 
allowed  to  accumulate  for  any  length  of  time,  it  gets  so  thick  that 
it  will  drop  off  from  the  walls  of  the  vat  and  come  through  on  the 
wire.  Slime  has  no  .fibre  to  speak  of  and  consequently  a  hole  is 
produced  in  the  paper  just  the  size  of  the  slime  spot.  It  may  not 
actually  make  a  hole  until  the  paper  reaches  the  calenders,  but 
it  is  sure  to  spoil  the  paper.  Furthermore,  it  is  very  likely  to 
cause  a  break,  and  in  addition,  the  slime  spots  oftp  stick  to  the 
wire,  causing  a  hole  in  the  paper  the  size  of  the  slime  spot  every 
time  the  wire  makes  a  revolution. 

The  screens,  in  order  to  work  properly,  must  be  attended  to 
just  as  faithfully  as  any  other  part  of  the  machine.  The  toe- 
blocks  of  the  trotters  should  always  be  kept  tight  and  sufficiently 
long  that  they  ride  the  cam,  dropping  into  the  depressions  and 
riding  over  the  top  of  the  cam  in  a  smooth  way.  Sometimes  these 
toe-blocks  get  worn  so  short  that  only  the  very  top  of  the  cam 
touches  the  toe-blocks.  Under  these  conditions  no  vibration  is 
produced  in  the  diaphragm  at  all.  If  one  diaphragm  is  out  of 
action  in  this  way,  it  reduces  the  screening  capacity  of  the  equip¬ 
ment  just  25  per  cent,  if  there  are  four  diaphragms  to  a  screen. 

In  the  event  of  there  being  more  than  one  screen  serving 
the  machine  (as  is  usually  the  case)  it  is  necessary  to  watch  care- 
■fully  the  operation  of  the  screens  with  reference  to  the  stock  sup¬ 
plied  them,  and  each  valve  should  be  opened  or  closed  in  propor¬ 
tion  to  the  capacity  of  the  screen  it  is  feeding.  If  there  is  any 


THE  MACHINE  ROOM 


287 

difference  in  the  capacities  of  the  screens,  it  is  probably  due  to 
the  cams  or  toe-blocks  being  worn,  or  some  other  thing  affecting 
the  oscillation  of  the  diaphragm.  Always  try  to  have  the  dia¬ 
phragm  operate  with  a  smooth  motion  which  will  produce  an  in¬ 
termittent  suction  under  the  screen  plates.  The  suction  is  to 
draw  the  fibres  through  and  the  pressure  caused  by  the  upward 
movement  of  the  diaphragm  afterwards  releases  the  fibres  on  top 
of  the  plates,  so  that  the  plates 'will  not  become  sealed.  This  is 
why  a  steady  suction  down  through  the  plate  (such  as  that  pro¬ 
duced  by  a  vacuum  pump)  would  not  do;  a  suction  of  this  kind 
would  soon  seal  the  slots  in  the  plate. 

Another  point  worth  bearing  in  mind  is  that  large  particles  of 
fibre,  dirt,  shieves,  and  slivers  are  inclined  to  float,  and  if  careful 
judgment  is  exercised,  most  of  these  can  be  floated  to  tbe  dry  end 
of  the  screens  where  they  can  be  removed  with  a  wooden  pointed 
shovel. 

The  screen  plates  should  never  be  scraped  with  metal  harder 
than  they  are  themselves.  This  produces  rough,  burr-like  projec¬ 
tions  on  the  plates  and  prevents  the  fibres  from  dropping  through 
the  slots.  In  other  words,  clean,  smooth  slots  of  the  right  size 
should  be  maintained  and  care  taken  that  nothing  is  done  to  get 
them  out  of  this  condition. 

In  taking  up  a  screen  for  a  general  washing,  if  chain 
falls  are  used  or  rope  tackle,  care  must  be  exercised  not  to  drop 
any  of  these  articles  on  the  screen  plates,  for  they  are  sure 
to  be  bent.  ^ 

It  is  customary,  and  quite  desirable,  in  almost  all  flat  screens, 
to  supply  a  shower  of  water  to  drive  and  float  the  material  to¬ 
ward  the  dry  end  of  the  screen.  These  showers  are  usually  pro¬ 
vided  by  a  shower-pipe  extending  crosswise  of  the  screen  at  some 
advantageous  point,  and  the  needle  streams  that  come  from  the 
shower-pipe  are  inclined  at  such  an  angle  as  to  sweep  the  plates 
in  the  most  efficient  manner.  With  some  grades  of  paper  white 
water  is  used  for  the  shower,  while  with  other  grades  nothing 
but  clear  fresh  water  is  used. 

When  the  screen  plates  are  put  into  a  screen  extreme  care 
should  be  taken  to  see  that  they  fit  perfectly  on  the  wooden  sills 
of  the  screen  body.  Every  screw  should  be  driven  home  so  that 
the  plate  will  lie  perfectly  flat  and  be  perfectly  water-tight  all 
around  the  edges.  Where  the  sills  have  become  worn,  a  thin 
sheet  packing  or  gasket  is  sometimes  used.  The  continued  use  of 
a  screen  vat  necessitates  screen  plates  being  taken  out  and  put 
in,  time  after  time.  Tbe  screws  go  back  into  tbe  same  hole  every 
time,  on  account  of  the  holes  being  drilled  through  the  plate  by  a 
template.  The  holes  in  the  sills  will  finally  become  so  worn 
that  the  plates  will  rise  or  unseat  every  time  there  is  an  up¬ 
ward  stroke  of  the  diaphragm,  thus  letting  through  an  im¬ 
mense  amount  of  dirt. 

The  only  cure  for  this  worn  condition  of  the  sills  is  to  renew 


288 


MODERN  PULP  AND  PAPER  MAKING 


them.  Sometimes  as  a  temporary  makeshift,  the  holes  can  be 
plugged,  but  this  it  not  generally  recommended. 

There  are  several  screwless  screen  plate  fasteners  on  the  mar¬ 
ket.  These  have  devices  by  which  the  plates  can  be  clamped  down 
and  fastened  in  tightly  without  screw  holes.  The  Witham  Screw¬ 
less  Screen  Plate  Fastener  is  typical  of  these  devices.  The  plates 
are  beveled,  and  beveled  cleats  of  special  form  hold  them  in  posi¬ 
tion,  obviating  the  use  of  screws,  entirely. 

Another  point  in  connection  with  screens,  worthy  of  considera¬ 
tion,  is  that  the  upper  part  of  the  screen  body,  carrying  the  plates, 
should  always  be  carefully  screwed  or  clamped  to  the  screen  vat 
and  packing  used  to  prevent  this  joint  from  leaking  stock.  The 
screens  are  sometimes  placed  in  such  a  manner  that  it  is  hard  for 


Courtesy:  Union  Screen  Plate  Co.,  Fitchburg,  Mass. 

Fig.  1 15. — Vat  of  diaphragm  screen  showing  Witham  screwless  screen 

plate  fastener. 

the  workmen  to  get  at  the  clamps  to  unscrew  them,  and  in  order 
to  get  them  apart,  the  help  sometimes  use  hammers,  bars  or 
weights.  After  releasing  them  a  few  times  in  this  manner,  the 
fastenings  become  useless.  Good  fastenings  with  proper  packing 
will  always  keep  the  screen  body  tight,  if  treated  with  care.  Leaks 
through  the  joint  between  the  upper  and  lower  parts  of  the  screen 
body  are  bad  because  they  reduce  the  suction  under  the  plates, 
and  maintain  an  untidy  and  wasteful  mess  of  stock  on  the  floor. 

It  may  be  that  some  machine  tenders  have  the  erroneous  idea 
that  by  having  the  screen  plates  cut  as  fine  as  possible  that  it 
makes  paper  cleaner.  The  idea  being  that  the  finer  the  slot  the 
less  the  large  particles,  such  as  shieves  and  dirt,  will  go  through. 

This  idea  of  course  is  all  right  up  to  a  certain  limit,  but  where 
screen  plates  are  so  fine  that  they  need  constant  stirring,  it  is 
very  detrimental  to  making  clean  paper. 

The  slots  in  the  plates  must  be  large  enough  to  permit  of  the 
stock  going  through  readily  without  being  stirred.  For  instance, 
if  14  cut  plates  were  being  used  and  it  were  necessary  to  stir 
the  screens  constantly  to  get  the  stuff  through,  it  would  be  far  bet¬ 
ter  to  change  these  14  for  16  cut  plates. 


THE  MACHINE  ROOM  289 

The  exact  limit  must  be  determined  by  the  kind  of  paper  and 
the  amount  of  work  screens  are  required  to  do. 

It  is  very  poor  judgment  to  equip  any  paper  machine  with  a 
scant  screen  capacity,  because  the  necessity  of  stirring  the  screens 
frequently  not  only  delivers  a  lot  of  fine  dirt  through  into  the 
paper,  but  it  also  interrupts  the  weight  of  the  paper.  When  the 
accumulated  fibre  in  the  screens  is  released  by  scraping,  the 
weight  of  the  paper  increases.  Since  the  drying  is  properly  set 
for  a  certain  weight  of  paper,  the  increase  in  weight  will  make 
the  paper  wet.  When  the  screens  are  filling  up  the  result  follow¬ 
ing  would  be  exactly  the  reverse.  In  other  words  the  paper 
would  bcome  too  light  and  dry.  This  would  necessitate  constant 
changing  of  the  steam  pressure  in  the  dryers  and  would  give  all 
sorts  of  ditferent  weights  to  the  paper,  change  its  texture,  change 
the  moisture  contained  in  the  paper  and  cause  no  end  of  trouble. 
The  screens  must  be  adequate  for  the  supply  of  the  machine  and 
the  plates  must  be  of  such  cut  as  will  permit  all  of  the  stock  to 
go  through  without  constant  stirring  and  attention. 

As  before  stated,  the  best  condition  is  to  have  the  stock  flow 
into  the  upper  end  of  the  screen  and  go  through  without  stirring 
and  have  the  large  particles  of  dirt  and  shieves  flow  out  onto  the 
opposite  end  of  the  screen  onto  dry  plates,  where  it  can  be  care¬ 
fully  removed  with  a  wooden  pointed  scoop. 

Rotary  Screens. 

Some  paper  makers  prefer  rotary  screens  to  diaphragm  screens 
because  they  believe  that  the  advantages  of  this  type  of  equip¬ 
ment  more  than  outweigh  the  somewhat  increased  complexity  of 
the  mechanism. 

The  advantages  claimed  for  rotary  screens  over  diaphragm 
screens  are  as  follows :  With  a  fixed  flat  bed  screen  plates  cannot 
be  maintained  at  a  uniform  or  constant  degree  of  cleanness  for 
flat  plates  accumulate  dirt ;  they  fill  up  and  foul  until  it  becomes 
necessary  to  wash  up.  Consequently,  there  is  a  period  just  be¬ 
fore  washing  up  when  the  stock  is  dirty.  By  building  the  screen 
plates  in  cylindrical  form,  as  in  the  rotary  or  revolving  screen,  it 
is  possible  to  keep  the  plates  clean  all  the  time  by  a  continuous 
shower. 

In  spite  of  these  advantages,  the  universal  introduction  of  the 
rotary  screen  has  been  delayed  waiting  for  a  rotary  screen  that 
would  combine  efficient  service  with  simple  and  substantial  con¬ 
struction,  large  capacity  and  long  service. 

Several  makes  of  rotary  screens  are  now  on  the  market  which 
have  proved  very  satisfactory  in  operation.  These  are  mainly 
of  two  types :  inward  flow  screens  and  outward  flow  screens. 

Bird  Inward  Elow  Rotary  Screen:  This  is  a  very  satisfac¬ 
tory  screen  for  all  grades  of  stock  except  those  containing  long, 
slow  working  fibres  such  as  the  stock  for  bonds,  ledgers,  writings, 
etc.,  which  usually  contain  a  large  proportion  of  rag  stock. 


290 


MODERN  RULE  AND  PAPER  MAKING 

The  inward  flow  type  of  rotary  screen  permits  of  greater  ca¬ 
pacity  than  the  outward  flow  type  and  consequently  is  desirable 
wherever  it  can  be  used.  It  is  suitable  for  newsprint,  hook  paper, 
sulphite  and  mixed  bonds,  bag  and  wrapping  papers,  ground 
wood,  and  sulphite  box  board,  chip  board,  roofing  felt,  rope,  jute 
and  sulphite  specialties,  etc. 

The  following  is  a  description  of  the  operation  and  construc¬ 
tion  of  this  screen : 

Unscreened  stock  enters  through  flow  boxes  A  and  B,  each 
placed  above  the  vat  and  discharging  downward  against  cylinder 
C.  The  stock  is  screened  through  the  slowly  revolving  cylinder 


WINCED  PAN 


CYLINDER 


LAMINATED  VERTICAl 
SPHINC  SUPPORTINC 
«AT  BRACKET 


Courtesy :  Bird  Machine  Co.,  East  Walpole,  Mass. 

Fig.  1 16. — Bird  inward  flow  rotary  screen. 


and  flows  through  the  open  end  to  discharge  box  R  which  is  con¬ 
nected  to  the  head  box  of  the  paper  machine  by  a  spout  or  pipe, 
as  best  suits  the  particular  installation. 

Impurities  held  back  by  the  plates  settle  toward  drain  E,  the 
down-coming,  unscreened  stock  assisting  gravity  in  this  action, 
and  are  removed  in  a  small,  constant  stream  to  the  auxiliary 
screen.  This  auxiliary  screen  may  be  a  flat  screen  already  used 
in  the  mill,  or  a  specially  designed,  two  plate  flat  screen,  equipped 
with  cleaners,  will  have  sufficient  capacity  to  handle  this  tailing 
stock.  Impurities  are  removed  from  the  top  of  the  auxiliary 
screen  and  disposed  of  as  ma’"  be  desired,  while  the  screened 
stock  from  the  auxiliary  unit  is  returned  to  the  flow  box  of  the 
rotary  screen  to  be  rescreened  before  passing  to  the  paper  ma¬ 
chine.  It  is  usually  possible  to  pipe  the  screened  stock  from  the 
auxiliary  screen  to  the  white-water  fan  pump  and  use  this  medium 
for  returning  the  stock  to  the  rotary  screen.  Where  this  method 


THE  MACHINE  ROOM 


291 


is  not  possible,  or  con¬ 
venient,  a  I  ^ -inch 
centrifugal  pump  may 
be  installed  as  an  in¬ 
dependent  unit. 

The  slots  in  the 
cylinder  are  cleaned 
by  shower  H.  Winged 
pan  I  serves  both  as  a 
guard  against  splash¬ 
ing  and  also  as  a  tray 
to  catch  the  water 
which  is  driven 
through.  Tray  J 
catches  the  water 
w  h  i  c  h  strikes  the 
cylinder  and  falls 
back. 

The  body  of  the 
vat  K  is  of  3-16-inch 
boiler  plate,  copper- 
lined,  and  rests  in 
two  semi-circular 
brackets  L,  one  end 
of  which  is  supported 
by  two  vertical,  lami¬ 
nated  springs  M,  sim¬ 
ilar  to  Fourdrinier 
supports,  and  the 
other  by  a  double 
pivot  N.  From  this 
pivot  extends  the 
shake  arm  O,  con¬ 
nected  by  a  rod  to  an 
eccentric  P.  Raising 
or  lowering  the  posi¬ 
tion  of  the  rod  in¬ 
creases  or  decreases 
the  length  of  the 
stroke.  The  eccentric 
is  a  5-inch  cast-iron 
cam  running  in  a 
bronze-lined  shell. 

The  cam  is  bored  off  center  5-16  of  an  inch  and,  while  running 
at  a  speed  of  350  revolutions  per  minute,  produces  an  easy  but 
effective  shake  upon  the  vat.  The  vat  body  is  connected  to  the 
fixed  heads  by  strips  of  pure  rubber.  The  cylinder  itself 
is  not  shaken,  nor  is  it  subject  to  violent  action  as  are  the  dia¬ 
phragms  in  a  flat  screen. 


292  MODERN  PULP  AND  PAPER  MAKING 

One  end  of  the  cylinder  is  closed,  and  a  shaft  attached  to  the 
head  passes  through  the  vat  by  means  of  a  simple  stuffing  box. 
The  shaft  is  driven  by  heavy  cast-iron  gears  (standard  pattern) 
which  reduce  the  speed  from  the  driving  shaft.  These  gears  will 
last  indefinitely,  for  they  are  easily  lubricated  and  stock  or  water 
never  reaches  them. 

The  discharge  end  of  the  cylinder  is  carried  in  a  bronze-ljned 
ring  bearing.  A  double  set  of  packing  strips  makes  a  tight  joint 
between  the  cylinder  and  the  vat  so  that  it  is  impossible  for  un- 


Courtesy:  Bird  Machine  Co.,  East  IValpole,  Mass. 

Fig.  ii8. — Walpole  outward  flow  rotary  screen. 

screened  stock  to  get  outside  of  tbe  cylinder  and  leak  into  tbe 
screened  stock  flowing  from  inside. 

It  is  claimed  by  the  makers  of  this  screen  that  only  one-quarter 
as  much  power  is  required  as  for  the  operation  of  the  diaphragms 
of  flat  screens.  They  also  claim  that  plates  cost,  less  by  the  year 
when  used  in  a  rotary  screen.  The  plates  of  this  class  of  screen 
are  interchangeable,  reversible  and  easily  replaced. 

The  IValpole  Outzmrd  Elozv  Rotary  Screen:  This  screen  is 
specially  adapted  to  stock  containing  long,  slow  working  fibre  sucii 
as  is  used  for  high  class  rag  papers.  It  is  an  adaptation  of  the 
Wandel  screen.  The  following  is  a  description  of  the  construc¬ 
tion  and  operation  of  this  screen :  In  construction  the  Walpole 


THE  MACHINE  ROOM 


293 


Screen  consists  of  a  cast-iron  vat  and  frames  amply  heavy  to 
stand  lip  and  give  long  service.  The  vat  is  lined  with  copper, 
which  prevents  corrosion  and  discoloration  of  the  stock.  The 
cylinder  plates  are  made  of  specially  rolled  phosphor  bronze. 
The  cylinder  heads  are  of  cast  brass  finished  to  offer  a  smooth 
surface  to  the  stock.  All  fittings  which  come  in  contact  with  the 
stock  are  made  of  copper. 

The  stock  is  spouted  into  the  cylinder  through  a  hollow  jour¬ 
nal  at  the  end;  it  drops  to  the  bottom  of  the  cylinder,  passes 
through  the  slots  into  the  vat,  and  thence,  to  the  paper  machme. 
The  rejections  and  impurities  are  carried  up  with  the  revolving 
cylinder  and  are  washed  out  through  the  discharge  pan  by  the 
shower.  The  cam  shaft  fitted  with  a  six-pointed,  round-faced 
cam  at  either  end  imparts  an  easy  shake  to  the  cylinder.  This 
light,  but  positive  vibration  shakes  out  the  massed  fibers  and  ef¬ 
fectively  puts  them  through  the  screen  plates  well  brushed  out 
and  ready  for  the  paper  machine.  The  only  moving  parts  on  a 
Walpole  Screen  are  (i)  the  cylinder,  (2)  the  pivoted  bearings 
which  support  the  cylinder,  and  (3)  the  cam  shaft. 

One  pulley  24x4  inches  constitutes  the  drive,  which  requires 
but  I  H.P.  Oil  and  grease  cups  are  provided  for  convenient 
lubrication. 

Head  Boxes, 

The  head  box  of  a  Fourdrinier  paper  machine  is  usually  con¬ 
structed  of  from  three  to  four  inches  of  hard  pine  or  cypress 
plank,  and  perfectly  tight.  These  boxes  are  usually  strengthened 
with  iron  rods.  The  design  of  the  head  box  should  be  such  that 
it  will  deliver  the  entire  flow  of  water  and  pulp  mixture  from 
the  screens  onto  the  apron  and  wire  thoroughly  mixed  and  not 
rushed  on  with  any  undue  pressure  which  would  create  currents 
and  boiling  action.  Also  the  stock  should  come  up  to  the  last 
opening  and  be  delivered  onto  the  apron  in  a  smooth  sheet  of 
stock,  the  full  width  of  the  machine.  This  stock  should  be  thor¬ 
oughly  mixed,  the  fibres  drawn  out  and  separated. 

When  a  head  box  is  so  constructed  that  one  can  see  streaks  of 
water  and  streaks  of  stock  flowing  onto  the  wire,  apparently 
separated,  arousing  the  homely  expression  that  one  can  see  a 
streak  of  fat  and  a  streak  of  lean,  meaning  by  this  that  the  stock 
is  not  thoroughly  mixed,  it  is  not  of  the  right  construction  and 
should  not  be  used. 

A  head  box  usually  has  two  or  more  compartments.  The 
stock  is  usually  delivered  at  the  back  of  the  box,  taking  it  di¬ 
rectly  from  the  screen  spout.  Sometimes  it  is  put  into  the  box 
at  the  top,  and  allowed  to  fill  the  first  compartment,  striking 
against  the  partition  and  coming  up  and  over  the  edge  of  the  last 
partition  and  onto  the  apron. 

The  size  of  this  head  box  is  determined  entirely^  by  the  vol¬ 
ume  of  stock  and  water  that  has  to  be  handled.  Different  con- 


MODERN  PULP  AND  PAPER  MAKLSG 


294 

ditions  require  a  little  different  construction  to  meet  them.  Some¬ 
times  it  is  necessary  on  account  of  the  location  of  the  screen  to 
enter  the  stock  down  low  where  it  first  goes  into  the  head  box. 
In  this  case  the  first  partition  next  to  the  intake  goes  clear  to  the 
bottom  and  the  stock  in  this  case  has  to  flow  over  the  top  of  the 
first  partition  and  underneath  the  next  one.  All  of  this  is  meant 
to  spread  the  stock,  to  produce  the  mixture  uniformly  or  draw 
it  out  as  mentioned  above.  There  is  also  provided  an  overflow 
at  the  back  side  of  the  flow  box  so  that  in  the  event  of  a  gush 
of  water  caused  by  the  screens  filling  up,  by  the  uneven  flow  of 
pumps  or  by  opening  valves  at  the  intake  of  the  screens,  etc.,  this 
overflow  will  pass  from  the  end  of  the  head  box  around  into  the 
pump  box  and  to  the  screens.  A  gush  of  water  distributed  in 
this  way  will  not  as  a  rule  cause  any  breaks  or  trouble  on  the 
machine,  if  it  is  worked  carefully. 

If  tke  wire  should  stop  (from  the  breaking  of  a  belt  or  the 
slipping  of  a  couch  roll  or  for  any  reason)  so  that  the  stock  must 
he  shut  off  suddenly  before  the  machine  can  be  closed  down  in 
the  regular  way,  the  outlet  to  the  apron  would  have  to  be  shut  off 
quickly  while  the  stock  was  still  flowing  into  the  screen  and  head 
box.  This  overflow  would  take  care  of  the  most  of  this  violent 
gush  of  water  and  flood  the  wire  but  little.  The  head  box  is 
also  usually  equipped  with  a  lip  at  the  outlet  where  the  stock  is 
distributed  onto  the  apron  and  this  lip  can  be  raised  by  means  of 
hinges  on  the  underside.  This  lip  is  called  the  apron-board  and 
carries  the  apron  across  the  breast  roll.  When  a  wire  has  to  be 
put  on,  this  hinge  on  the  apron-board  permits  swinging  it  back 
out  of  the  way,  thus  giving  ample  room  to  take  out  the  breast 
roll  without  difficulty. 

Apron. 

The  apron  is  a  shallow,  flexible  trough,  through  which  the 
stuff  flows  onto  the  wire,  thus  bridging  over  the  open  space  be¬ 
tween  the  breast  roll  and  head  box.  The  slices,  which  are 
metal  dams  with  perfectly  level  under  edges,  set  vertical  to  the 
surface  of  the  wire,  dam  back  the  stock,  filling  the  apron  full  of 
water  containing  pulp  fibres  and  this  is  called  the  pond.  The 
slices  are  raised  one  inch  or  less,  from  the  wire  so  as  to  allow  all 
the  water  and  fil)res  to  flow  onto  the  wire.  The  force  with  which 
the  stock  comes  out  of  the  pond  and  under  the  slices  is  in  direct 
proportion  to  the  height  of  the  water  in  the  pond.  This  head  is 
regulated  by  the  supply  of  stock  and  also  by  the  height  of  the 
slices  from  the  wire.  Without  changing  the  stock  supply,  the 
slices  can  be  lowered,  reducing  the  area  of  the  outlet,  which  re¬ 
sults  in  hacking  iq)  the  stock  in  the  pond  to  a  greater  height.  'This 
performance  has  the  effect  of  gi\  ing  the  stuff  more  speed  as  it  is 
delivered  to  the  wire.  Reversing  this  process  gives  the  opposite 
results.  These  changes  must  be  governed  entirely  by  the  kind  of 
paper  being  made,  d'he  stuff  must  be  delivered  to  the  wire  at  as 


THE  MACHINE  ROOM 


295 


near  the  speed  of  the  wire  as  possible.  The  slices,  in  conjunction 
with  the  shaking  of  the  wire,  are  what  spread  the  fibres  evenly 
and  uniformly. 

The  slices  when  set  very  low  catch  the  fibres  and  turn  them  on 
end,  causing  the  sheet  to  have  a  broken,  unfelted  appearance. 
This  is  more  noticeable  when  working  long  stuff,  and  it  is  the 
cause  of  the  wavy  streaked  appearance  of  thick  sheets.  The 
thicker  the  sheet  the  more  shake  is  required  to  felt  it  and  when 
making  a  thick  paper,  such  as  certain  bag  and  wrapping  papers, 
for  which  the  stuff  has  been  made  long,  the  slices  will  have  to  be 
raised  so  that  enough  water  may  be  worked  in  to  assist  in  closing 
the  fibres. 

In  starting  a  run  the  lower  edge  of  the  apron  should  be  within 
about  an  inch  of  the  first  slice.  This  distance  may  often  have 
to  be  varied  later,  depending  on  the  particular  kind  of  sheet 
being  produced.  When  making  a  thin  sheet  from  free  stock, 
where  there  is  difficulty  in  carrying  the  water  nearly  to  the  suc¬ 
tion  boxes,  the  moving  of  the  apron  clear  down  to  the  first  slice 
will  assist.  Conversely  when  making  a  thick  sheet  from  slow 
stuff  the  apron  should  be  pulled  back,  possibly  as  much  as  two 
inches,  depending  on  conditions  to  be  met. 

Slices. 

The  slices  are  sheets  of  brass,  ordinarily  from  6  to  12  inches 
wide  and  about  ^-inch  thick.  They  are  placed  across  the  wire 
vertical  to  the  surface  of  the  wire.  They  are  made  in  two  sec¬ 
tions  which  slip  by  each  other  in  such  a  manner  that  the  length 
of  the  slice  may  accord  with  the  width  of  the  sheet  of  paper  being 
made.  When  the  length  of  the  slice  is  determined,  the  sliding 
device  is  held  firm  by  thumbscrews.  A  device  is  also  provided 
for  up  and  down  adjustments  so  as  to  regulate  the  even  distribu¬ 
tion  of  the  stuff  on  the  wire. 

As  previously  mentioned,  when  speaking  of  the  apron,  in  mak¬ 
ing  all  grades  and  weights  of  paper,  the  slices  should  be  so  ad¬ 
justed  that  the  speed  of  the  wire  and  that  of  the  stock  will  be 
as  near  equal  as  possible.  This  result  is  obtained  by  the  pressure 
of  the  head  behind  the  slices  (assisted  by  the  pitch  of  the  wire 
in  some  machines) .  Some  machines,  especially  modern  high  speed 
news  machines,  give  a  high  degree  of  pitch  to  the  wire,  sometimes 
the  difference  in  elevation  of  the  two  ends  of  the  wire  being  as 
much  as  18  inches. 

Slices  are  carried  high  on  free  stuff  in  order  to  supply  the 
great  amount  of  water  needed  in  free  stuff  to  properly  close  it  on 
the  wire  before  it  reaches  the  suction  boxes.  On  slow  stuff  the 
slices  must  be  carried  close  to  the  wire  in  order  to  reduce  the 
quantity  of  water.  This  is  due  to  the  comparative!}'  small  amount 
of  water  that  will  drain  out  of  slow  stuff  on  the  wire.  In  most 
cases  when  making  heavy  paper,  the  slices  are  carried  close  to  the 
wire,  excepting  when  the  stock  is  free,  when  they  must  be  prop- 


296  MODERN  PULP  AND  PAPER  MAKING 

erly  raised  to  close  the  sheet.  The  slices  are  a  very  important 
factor  in  making  a  paper  that  must  be  close  and  uniform  (in 
looking  through).  Generally  speaking,  when  making  the  lighter 
weights  of  paper,  the  best  results  are  obtained  by  only  using  one 
slice,  especially  if  the  machine  is  running  more  than  200  feet  per 
minute ;  otherwise  the  sheet  is  likely  to  be  blemished  with  bar 
marks  running  across  it.  When  using  two  slices,  the  first  slice 
should  be  twice  the  distance  from  the  wire  of  the  second  one. 
This  causes  a  current  between  the  two  and  insures  a  thorough 
mixing  of  the  fibres  just  before  they  pass  the  last  slice.  The 
width  of  the  deckle  also  influences  the  position  of  the  slices.  The 
slices  on  a  narrow  deckle  must  necessarily  be  carried  higher  than 
on  a  wide  deckle;  in  fact,  the  whole  matter  may  be  summed  up 
as  a  question  of  obtaining  the  proper  head  behind  the  slices  to 
equalize  as  nearly  as  possible  the  flow  of  stuff  with  the  speed 
of  the  wire. 

Fourdrinier  Wires. 

The  strands  of  the  Fourdrinier  wire  are  made  of  especially 
annealed  copper  or  brass,  very  finely  drawn  and  woven  into  a 
web  usually  from  60  to  70  wires  to  the  inch,  60  being  the  most 
ordinary  number  as  can  readily  be  determined  with  an  ordinary 
)4-inch  linen  tester  which  should  show  15  strands  of  wire  to  the 
square  opening.  Much  finer  wires  are  used  for  some  special 
papers,  such  as  cigarette  paper.  The  wire  is  joined  at  the  ends 
making  an  endless  belt  of  wire  cloth.  Wire  analyses  show  ordi¬ 
narily  80  per  cent  copper  and  20  per  cent  zinc. 

The  pulp  fibres  must  be  thoroughly  crissed-crossed  and  inter¬ 
woven  on  the  wire  while  they  are  being  formed  into  the  film  or 
web.  This  is  the  only  place  on  the  paper  machine  where  the  fibres 
can  be  interwoven  and  properly  felted  so  consequently  everything 
must  at  all  times  be  in  first  class  condition.  To  assist  in  inter¬ 
weaving  the  fibres  a  shaking  or  sifting  motion  is  imparted  to 
the  shake  rails  which  carry  the  tube  rolls  and  wire.  This  is 
known  as  the  “shake”  of  the  wire.  Assuming  that  there  is  only 
15  feet  to  20  feet  of  making  up  surface  (this  length  depending 
on  the  machine),  on  the  wire,  and  with  the  machine  running, 
let  us  say  five  hundred  feet  per  minute,  it  is  evident  that  only  a 
very  small  part  of  a  minute  is  allowed  for  forming  the  paper. 
The  speed  at  which  the  machine  is  to  be  driven,  and  the  nature 
of  the  stock  to  be  worked,  must  always  be  taken  intO'  consideration 
when  specifying  the  length  of  the  wire  to  be  used.  For  the 
proper  working  of  short,  soft,  greasy  stuff  at  the  correct  speed, 
a  long  wire  is  an  advantage,  thereby  giving  more  time  to  allow 
the  water  to  be  taken  out ;  but  for  fine,  long  stuff,  not  too  soft, 
worked  at  a  moderate  speed,  a  short  wire  will  be  best  suited. 
The  speed  must  also  determine  the  amount  of  pitch  or  inclination 
to  be  given  to  the  wire. 

In  the  case  of  high  speed  news  machines  (as  mentioned  above) 


THE  MACHINE  ROOM 


297 


running  constantly  600  feet  a  minute  or  more,  the  wire  may 
be  raised  at  the  breast  roll  end  as  much  as  16  or  18  inches  to 
give  the  necessary  speed  to  the  stuff.  If  the  stuff  were  moving 


slower  than  the  wire,  the  sheet  would  be  rough  and  not  properly 
felted  and  if  the  stuff  should  run  faster  than  the  wire  it  would 
accumulate  in  puddles  causing  streaks. 


298  MODERN  PULP  AND  PAPER  MAKING 

It  will  be  noticed  that  when  a  wire  after  running,  sometimes 
becomes  slack  on  either  of  the  edges,  it  is  generally  the  back  side, 
if  the  water  for  the  wash  roll  enters  at  the  front  side,  and  vice 
versa  if  the  water  enters  from  the  back.  The  reason  for  this  is 
that  the  small  holes  in  the  water  pipes  are  apt  to_  become  choked 
at  the  end  farthest  from  the  inflow,  and  the  wire  owing  to  its 
being  much  more  dry  is  strained  in  its  passage  over  the  rolls 
Apart  from  this  the  wash  roll  should  have  a  suitable  doctor  and 
a  good  strong  shower  in  order  that  any  pulp,  which  would  be¬ 
come  lodged  in  the  meshes,  may  be  washed  out. 

Attention  to  this  and  also  to  thoroughly  washing  the  wire, 
when  shut  down  for  any  length  of  time,  will  keep  the  meshes 
clear,  lessen  the  strain  on  the  suction  boxes,  and  improve  the  ap¬ 
pearance  of  the  sheet,  in-  addition  to  prolonging  the  life  of 
the  wire. 

Having  the  wire  too  slack  is  another  very  frequent  source 
of  “snap-offs”  or  crackings  and  breakings  in  the  sheet  between 
the  dryers  and  calenders.  When  the  wire  is  too  slack  the  seam  of 
it  is  apt  to  crease  the  paper  when  passing  under  the  couch  roll, 
but  in  such  a  way  that  it  is  scarcely  noticeable,^  unless  the  ma¬ 
chine  tender  knows  where  to  look  for  it.  This  is  most  liable  to 
happen  when  making  a  narrow  sheet  of  heavy  paper,  and  the 
first  thing  a  machine  tender  should  do  when  he  is  at  a  loss  to 
account  for  such  breaks,  is  to  hold  a  light  under  the  web  between 
the  under  couch  roll  and  the  wet  felt  roll,  so  that  he  may  make 
sure  if  any  creases  are  there.  If  the  wire  is  causing  creases  they 
will  appear  like  small  black  streaks  running  a  little  way  in  from 
the  edge.  Tightening  up  the  wire  a  few  turns  and  putting  more 
weight  on  the  couch  roll  will  cure  this. 

Causes  of  Wire  Deterioration. 

(1)  The  destructive  action  of  the  couch  roll  through  actual 
wear. 

(2)  The  pitch  pressed  into  the  wire. 

(3)  Foreign  substances  passing  through. 

(4)  Cleaning  the  wire  with  acids. 

(5)  Breaking  of  jackets. 

(6)  Accumulation  of  stock  on  the  wire,  breast  rolls  and 
carrying  rolls  through  ..the  use  of  imperfect  deckle  straps  and 
carelessness  and  above  all  the  operation  of  imperfect  shower  pipes 
with  inadequate  pressure.  This  may  be  corrected  by  concave 
deckles  and  installation  of  shower  pipes  delivering  a_  contimious 
and  unbroken  spray  of  water  at  from  twenty  to  thirty  pounds 
pressure. 

(7)  Improper  bearings  on  rolls  and  unbalanced  rolls. 

(8)  Rolls  out  of  alignment. 

(9)  Imperfect  guides  and  guide  rolls. 

( 10)  Deep  pond  over  the  apron  and  heavy  load  on  the  wire. 


THE  MACHINE  ROOM 


299 


Except  for  high  speed  machines  with  inclined  wire  there  seems 
to  be  no  adequate  means  for  relieving  this  load. 

(ii)  Floods  on  the  wire. 


(12)  Improperly  dressed  suction  box  covers. 

(13)  Inefficient  management  has  a  direct  bearing  on  shorten¬ 
ing  the  life  of  the  wire.  Lack  of  inspection,  lack  of  co-operation, 


300  MODERN  PULP  AND  PAPER  MAKING 

lack  of  incentiveness,  contribute  to  a  large  extent  to  shortening 
the  actual  life  of  a  wire. 

(14)  The  importance  of  protecting  the  wire  from  injury  in 
the  store  room  until  it  is  put  on  a  machine  is  frequently  under¬ 
estimated.  Unless  there  is  a  hearty  co-operation  and  a  real  sense 
of  responsibility  there  is  likely  to  be  trouble. 

(15)  Changing  of  wires.  It  is  necessary  that  the  proper 
facilities  should  be  at  hand  when  changing  a  wire.  All  parts  of 
the  machine  should  be  thoroughly  washed,  cleaned  and  freed 
from  slime  and  dirt.  No  foreign  material  or  stuff  should  be  left 
on  the  rolls,  for  this  will  cause  ridges.  Make  sure  before  start¬ 
ing  that  the  wire  is  perfectly  straight,  that  the  suction  boxes  are 
smooth,  and  that  there  is  no  greater  tension  on  the  wire  than  is 
absolutely  necessary. 

Putting  on  a  new  wire. 

The  wires  necessarily  being  very  fine  and  delicate,  extreme 
care  must  be  exercised  in  their  handling,  which  should  always  be 
done  by  competent  experienced  workmen.  A  bruise  or  kink  in 
these  wires  soon  causes  them  to  wear  or  break  through,  shorten¬ 
ing  their  service  to  a  great  extent. 

Defects  in  their  manufacture  should  be  observed,  if  possible, 
before  they  are  put  on  the  machine,  and  the  wire  should  then  be 
rolled  back  on  the  poles,  boxed  up  and  the  manufacturer  promptly 
notified  of  its  non-acceptance.  Slack  edges,  slack  centers,  poor 
seams  and  loops  in  the  filling,  known  as  slack  shots,  are  all  ob¬ 
jectionable  features.  It  is  advantageous  to  have  some  smooth 
clean  place  in  which  to  open  up  these  wires,  and  have  them  in¬ 
spected  by  a  man  who  is  competent  to  judge  them,  before  they  are 
put  on  the  machine. 

Wires  should  never  be  too  tight  when  started,  as  they  are 
thoroughly  stretched  before  leaving  the  factory,  and  any  undue 
strain  on  them  shortens  their  service.  On  large  machines  the 
weight  of  the  stretch  roll  is  generally  sufficient  at  the  beginning, 
it  not  being  necessary  to  screw  this  down. 

It  should  be  remembered  that  the  strands  of  a  Fourdrinier 
wire  are  not  elastic,  that  is  when  once  elongated  by  stretch  they 
will  remain  so.  Consequently,  the  zinre  should  never  be  stretched, 
zvhen  not  in  motion,  as  this  would  lead  to  a  permanent  stretch¬ 
ing  locally  whereas  if  stretch  is  applied  slowly  during  one  or 
more  revolutions  of  the  wire  the  stretching  effect  will  be  di.s- 
tributed  evenly  over  the  whole  surface.  Great  care  must  be 
taken  that  the  Fourdrinier  part  is  thoroughly  in  line  and  level. 
If  any  of  the  rolls,  especially  the  breast  roll,  is  out  of  line 
a  fractional  part  of  an  inch,  a  great  deal  of  trouble  is  caused  and 
the  wire  is  liable  to  be  run  into  a  wrinkle.  All  the  wire  rolls 
should  be  of  sufficient  size  and  strength  to  prevent  their  spring¬ 
ing  at  the  center,  as  this  usually  results  in  a  straight  wrinkle  in 
the  wire  which  soon  cuts  through  and  destroys  it. 


THE  MACHINE  ROOM 


301 


Starting  a  new  wire. 

Great  care  must  be  exercised  in  starting  a  new  wire,  first  being 
assured  that  everything  is  in  proper  condition  before  striking  in 
the  clutch,  which  operation  should  be  performed  very  gently  A 
clutch  should  never  grip  so  hard  that  the  wire  is  started  with  a 
jerk  It  IS  found  to  be  a.  very  good  plan  to  turn  the  wire  around 
slowly,  at  least  once  or  twice,  before  the  couch  is  set  down,  thus 
getting  the  wire  in  proper  alignment  before  starting  up. '  The 
stretch  roll  must  not  be  fastened  down  until  after  the  top  couch 
roll  is  lowered  into  place. 

Suction  boxes  should  be  thoroughly  dressed  (see  page  ...) 
so  that  the  covers  are  smooth  and  level ;  all  rolls  should  be  prop¬ 
erly  cleaned  ;  wire  guides  should  be  properly  adjusted.  The  seam 
of  the  wire  should  be  watched  closely  so  that  neither  end  will 
run  ahv.ad  of  the  other,  but  should  line  up  with  the  suction  box 
or  a  parallel  roll.  If  the  apron  is  held  in  place  by  copper  tacks 
it  is  very  essential  that  no  tacks  should  be  left  around  in  any 
place  where  they  can  get  into  the  wire.  All  particles  of  hard 
material  must  be  brushed  and  rinsed  off  before  the  wire  is 
started  up. 

The  breast  roll  should  be  supplied  with  a  doctor,  or  shoe, 
which  is  simply  a  level  edge  pressing  firmly  on  the  roll,  to  prevent 
stuff  collecting  on  it.  In  addition  to  this  there  should  be  a  very 
strong  shower  of  water  passing  through  and  in  front  of  the  roll, 
and  over  the  lip,  so  that  all  particles  of  stock  may  be  washed 
away.  There  are  different  designs  for  these  showers  and  doctors. 
In  some  cases  a  straight  piece  of  square  edged  board  covered 
with  felt  is  wedged  between  the  end  of  the  save-all  and  the 
breast  roll ;  in  other  -cases  a  wooden  doctor  leans  on  the  roll  and 
scrapes  off  the  stock,  which  collects  and  passes  into  the  save-all, 
and  under  which  is  the  shower  above  mentioned ;  anything  which 
the  doctor  does  not  remove  the  shower  will. 

If  for  any  reason  the  wire  is  stopped  and  the  stuff  shut  off, 
the  shake  should  also  be  stopped,  as  there  is  danger  of  shaking 
the  wire  into  a  wrinkle  when  it  is  not  loaded  with  a  sheet  of 
paper  and  held  down  by  the  suction  boxes.  If  anything  happens 
making  it  necessary  to  strike  the  wire  out  immediately  without 
fmst  having  a  chance  to  shut  off  the  stock,  such  stock  should  be 
thoroughly  rinsed  from  the  wire  before  attempting  to  start  again. 
The  weights  should  be  removed  from  the  couch  levers,  and  by 
all  means  the  suction  should  be  broken,  where  the  stock  has  sealed 
the  wire  over  the  top  of  the  suction  boxes.  This  can  be  done  by 
rinsing,  or  by  rubbing  the  fingers  across  the  top  to  break  the 
suction. 

Care  should  be  taken  to  let  up  on  the  guard-board  screws  be¬ 
fore  striking  the  wire  in,  as  many  times  the  couch  roll  jacket  is 
torn  off  by  neglecting  to  do  this.  The  guard-board  should  never 
be  let  down  onto  the  jacket  until  after  the  weights  have  been 


302  MODERN  PULP  AND  PAPER  MAKING 

applied  to  the  couch  rolls,  as  there  is  always  slack  enough  in  the 
couch  roll  boxes  so  that  if  the  guard-board  is  let  down  before 
the  weights  are  applied  this  slack  is  taken  up  in  the  boxes  and 
the  guard  box  will  necessarily  have  to  carry  the  weight  of  the 
weights  on  the  levers.  In  setting  the  guard-board,  great  care 
should  be  taken  to  lower  it  horizontally,  never  allowing  one  end 
to  go  down  before  the  other,  as  in  this  way  the  jackets  would  be 
tom  from  the  couch  roll. 

If  the  wire  does  not  guide  properly  when  started,  there  is  sure 
to  be  some  good  reason  for  it,  and  the  Fourdrinier  part  should  be 
very  carefully  examined.  No  attempt  should  be  made  to  guide 
the  wire  by  weighting  one  set  of  the  couch  levers  heavier  than 
the  other.  It  frequently  happens  that  the  suction  boxes  will  con¬ 
trol  the  guiding  of  the  wire.  It  may  run  all  right  without  any 
stock,  but  as  soon  as  the  sheet  is  put  onto  the  wire  and  the  suc¬ 
tion  boxes  take  hold,  the  wire  may  hang  to  one  side  or  the  other 
very  strongly.  Sometimes  this  can  be  averted  by  giving  the  suc¬ 
tion  box-heads  a  little  air,  or  swinging  one  end  slightly  out  of 

alignment.  . 

A  guide  roll  located  between  the  last  suction  box  and  the 
couch  rolls,  and  on  a  level  with  the  suction  box,  is  intended  to  keep 
the  wire  mnning  in  proper  alignment.  This  guide  roll  is  con¬ 
trolled  by  an  automatic  device  called  the  wire  guide,  which  tends 
to  immediately  correct  any  tendency  of  the  wire  to  get  out  of 
alignment.  The  guide  roll  is  rubber  covered,  and  the  wire  makes 
quite  a  sharp  bend  from  it  down  to  the  lower  couch  roll  thus  al¬ 
lowing  the  guide  roll  to  get  a  good  grip  on  the  wire. 

Care  must  be  taken  that  good  showers  are  furnished  for  the 
carrying  or  wash  roll  directly  under  the  couches.  The  shower 
must  strike  the  top  side  so  that  it  will  beat  off  the  stock  as  it  fol¬ 
lows  down  around  the  wire.  A  good  doctor  also  must  Pe  pro¬ 
vided  for  this  roll.  n  i  •  u 

Stock  should  never  be  allowed  to  pile  up  in  the  save-all  high 
enough  to  touch  the  wire.  The  cleaning  of  the  stretch  roll  is 
another  important  feature.  This  should  be  well  provided  with 
good  showers  so  that  all  particles  of  fibre  may  be  rinsed  away 
from  the  wire  and  the  roll. 

Deckles. 

The  Deckle  Straps  on  a  Fourdrinier  paper  machine  are  made 
endless,  of  soft  rubber;  2X2>4  inches  square  is  a  common  size. 
They  run  over  flanged  pulleys  like  an  endless  horizontal  belt,  the 
upper  strand  being  supported  by  the  flanged  pulleys,  and  the 
lower  strand  by  the  wire  which  carries  the  strap  along  with  it 
caterpiller  fashion  by  friction.  These  deckles  are  set  at  a  width 
^  corresponding  to  the  width  of  the  pond,  slices  and  apion,  and 
on  this  depends  the  width  of  the  sheet  being  made.  The  len^h 
of  the  deckle  is  from  the  pond  to  the  third  suction  box.  The 
flanged  pulleys  are  made  to  move  in  or  out — narrow  or  wide. 


THE  MACHINE  ROOM 


303 


When  they  are  moved  the  deckle  strap  moves  with  them.  In  this 
way  the  width  of  sheet  is  determined.  These  straps  are  very 
easily  injured.  The  slightest  crack  or  bruise  on  the  edge  will 
cause  the  paper  to  break  at  the  couchers,  presses,  dryers  and  cal¬ 
enders. 

The  deckle  straps,  as  they  lie  flat  and  square  on  the  wire, 
prevent  the  fibres  from  spreading — they  act  as  dams  inches 
high,  holding  the  stuff  on  the  wire.  The  edges  of  the  web  are 
moulded  against  the  straps  as  the  straps,  wire  and  stuff  are  all 
carried  forward  together.  In  order  to  mould  a  square  and  safe 
running  edge,  the  water  must  be  extracted  so  that  the  fibres  are 
dry  enough  to  stand  up,  after  leaving  the  straps.  It  is  for  this 
reason  that  two  or  three  of  the  suction  boxes  are  placed  under  the 
straps.  Modern  high-speed  machines  have  six  suction  boxes, 
three  placed  under  the  straps  and  three  between  the  straps  and 
the  couch. 

Deckle  straps  should  be  handled  with  extreme  care  when  put¬ 
ting  on  a  wire  or  making  other  repairs ;  avoiding  having  the  strap 
come  in  contact  with  any  sharp  edges  of  any  kind.  They  should 
never  be  tied  up  out  of  the  way  with  a  sharp  string;  a  broad 
piece  of  wool  felt  should  be  used  for  this  purpose. 

Spare  deckle  straps  should  be  kept  immersed  in  water  and 
never  should  be  wound  up  in  a  tight  roll.  New  deckle  straps 
should  be  unpacked  as  soon  as  received  and  laid  in  a  vat  of  water. 
If  necessary  for  any  reason  to  keep  a  deckle  strap  out  of  water 
for  any  length  of  time  its  position  should  be  changed  each  day, 
as  they  rapidly  harden  and  become  rigid  in  whatever  shape  they 
are  left  in.  Should  a  strap  become  nicked  on  the  edge,  or  other¬ 
wise  injured,  it  should  be  replaced  and  sent  to  the  factory  to 
be  reground.  No  oil  or  grease  should  be  allowed  to  come  in  con¬ 
tact  with  the  straps  as,  like  all  rubber  goods,  they  are  easily  ruined 
by  oil  or  grease. 

Tube  Rolls. 

The  Tube  Rolls  are  a  number  of  parallel  rolls  of  brass  tubing 
designed  to  support  the  wire  by  forming  a  level  table  on  which 
the  wire  runs.  Hence  they  are  often  called  table  rolls-  Those  at 
the  breast  roll  end,  and  under  the  pond  and  slices,  should  be  some¬ 
what  larger  than  those  forming  the  balance  of  the  table  to  pre¬ 
vent  springing  under  the  excess  weight  of  the  pond.  If  a  tube 
roll  gets  out  of  order  it  should  be  replaced  at  once,  as  the  wire 
running  over  a  stationary  roll  would  soon  wear  a  flat  place  on  the 
roll.  The  machine  tender  should  also  look  out  for  rolls  with 
sprung  journals,  as  these  will  cause  the  roll  to  be  off  center  with 
the  result  that  it  produces  an  elevation  in  the  wire,  each  revolu¬ 
tion  puddling  the  stock  and  causing  thick  streaks  in  the  paper. 
If  a  roll  can’t  be  kept  running  it  is  always  best  to  lower 
it  out  of  touch  with  the  wire  until  it  can  be  replaced  by  an¬ 
other  one. 


MODERN  PULP  AND  PAPER  MAKING 


304 

Suction  Boxes. 

Suction  boxes  are  long,  narrow,  brass  boxes  fitted  with 
wooden  covers,  perforated  with  round,  one-half  inch  holes  or 
other  openings,  so  arranged  that  every  particle  of  paper  that 
passes  over  them  comes  in  direct  contact  with  the  suction  without 
breaking  the  paper.  In  Europe  these  are  often  called  pump 
boxes.  The  holes  frequently  flare  a  little  from  the  under  side 
so  that  accumulations  of  slime,  etc.,  will  tend  to  drop  out.  To 
the  under  side  of  each  suction  box  is  attached  a  set  of  pipes, 
leading  to  a  vacuum  pump  regulated  by  valves,  so  that  the 
vacuum  can  be  regulated  on  each  individual  box.  Furthermore, 
plungers  are  attached  at  the  ends  of  these  boxes  which  can 
be  moved  in  and  out  in  accordance  with  the  width  of  the  sheet. 
As  the  layer  of  fibres  in  water  touches  the  machine  wire  there 
is  approximately  99^  per  cent  water,  but  as  the  layer  of  fibres 
passes  over  the  box  on  the  top  side  of  the  wire,  water  is  drawn 
out  through  the  suction  holes  and  pumped  away,  leaving  about 
85  per  cent  of  water  in  the  thin  sheet  before  it  passes  between 
the  couch  rolls  and  on  through  the  press  rolls  and  dryers. 

When  a  suction  cover  is  dressed  it  should  be  done  after  the 
cover  is  screwed  on  the  box,  the  whole  box  being  removed  and 
supported  on  two  horses  at  each  end,  just  as  it  is  supported 
in  the  machine.  Otherwise  the  top  of  the  box  will  appear  true 
until  placed  on  the  machine  when  it  will  be  found  to  sag  slightly 
in  the  middle.  The  millwright  should  use  a  jointer,  not  a  jack 
plane,  and  an  accurate  straight  edge. 

Dandy  Rolls. 

The  function  of  the  dandy  roll  is  to  smooth  down  the  surface 
of  the  sheet  while  it  is  still  in  formation  and  capable  of  being 
moulded.  Moreover,  the  dandy  roll  is  used  to  watermark  the  pa¬ 
per,  in  grades  where  a  watermark  is  desirable,  although  recently 
other  means  of  watermarking  paper  have  been  devised.  How¬ 
ever,  watermarking  with  dandy  rolls  is  still  the  general  practice. 
The  usual  purpose  of  a  watermark  is  to  identify  the  paper  of  a 
given  manufacturer.  It  is  usually  a  name  or  a  trade-mark,  al¬ 
though  watermarks  for  purely  ornamental  purposes  are  sometimes 
employed. 

The  dandy  roll  must  be  very  light  in  construction  and  yet 
rigid  enough  not  to  spring.  It  must  be  sufficiently  open  in  con¬ 
struction  that  it  will  not  fill  up,  since  if  even  a  spot  on  the  dandy 
is  filled  up  it  will  lift  the  paper  at  that  point.  There  is  no  shaft 
running  through  the  center  of  the  dandy.  It  is  a  fabricated  roll, 
being  made  up  of  comparatively  heavy  wire,  supporting  lighter 
wire  outside.  The  journals  are  attached  to  discs  at  each  end. 

The  dandy  roll  is  usually  placed  between  the  suction  boxes. 
If  a  machine  has  six  suction  boxes  under  the  wire,  four  are  be¬ 
hind  the  dandy  and  two  are  ahead  of  it.  The  four  behind  pre- 


THE  MACHINE  ROOM  305 

pare  the  sheet  for  the  action  of  the  dandy  and  the  two  following 
suck  it  dry  ready  for  the  couch  rolls. 

The  dandy  should  never  be  placed  right  over  a  tube  roll.  It 
should  be  placed  between  two  tube  rolls,  but  the  distance  between 
centers  should  never  be  so  great  as  to  allow  any  sagging  of  the 
wire  under  the  dandy. 

The  dandy  is  supported  in  “U”  shaped  bearings  in  such  a  man¬ 
ner  that  the  weight  of  the  dandy  always  rests  on  the  paper.  It 
must  never  drag  on  the  paper. 

The  circumference  of  the  dandy  is  so  calculated  that  the  wa¬ 
termark  will  register  in  just  the  right  place  on  the  sheet.  That 
is,  if  one  is  making  note  paper  or  typewriter  paper  of  a  certain 
size  it  is  desirable  to  hav/e  the  watermarks  come  so  that  when  the 
sheet  is  cut  up  the  watermarks  will  be  in  the  center  of  the  sheets 
and  not  at  the  edges  or  chopped  up  by  the  cutting.  It  is  possible 
to  do  this  with  wonderful  precision.  The  paper  on  which  the 
postage  stamps  of  many  countries  are  printed  is  so  made  that 
when  the  sheets  are  printed  one  watermark  comes  exactly  in  the 
middle  of  each  stamp.  Shrinkage  of  the  paper  has  to  be  con¬ 
sidered  in  this  connection. 

In  a  mill  making  fine  writing  paper  or  government  papers  for 
bonds,  postage  stamps,  documents,  etc.,  a  large  assortment  of 
dandy  rolls  has  to  be  kept  on  hand.  Some  of  these  rolls  are  very 
expensive,  especially  in  connection  with  intricate  watermarks  (for 
instance  the  large  coat-of-arms  of  the  United  States  used  on 
some  government  stationery)  and  this  is  an  important  item  in 
such  mills. 

Of  course,  many  mills  not  making  any  watermarked  paper  use 
dandy  rolls  for  smoothing  out  the  sheet,  but  such  dandys  are 
much  simpler  and  less  expensive  than  those  used  for  watermark¬ 
ing. 

If,  on  looking  across  under  the  wire,  directly  beneath  the 
dandy,  the  wet  streak  always  present  under  the  dandy  at  the  point 
where  it  touches  the  paper,  does  not  run  right  across  the  sheet, 
it  is  an  indication  that  the  dandy  is  not  pressing  hard  enough  on 
the  paper  at  the  side  where  the  sheet  is  dry,  that  is,  it  is  riding  in 
the  journals,  which  must  be  adjusted  to  correct  this  defect. 

The  dandy  is  usually  kept  clean  with  a  shower  from  a  pipe 
supported  by  the  supports  of  the  dandy  roll.  Back  of  this  shower 
is  a  wiper  which  keeps  the  dandy  smooth  and  free  from  stock  so 
that  when  it  comes  in  contact  with  the  paper  it  is  perfectly  clean. 
Some  dandy  rolls  have  internal  showers,  which  is  done  by  run¬ 
ning  a  shower  pipe  through  hollow  journals. 

It  is  easy  to  tell  when  the  dandy  needs  a  thorough  cleaning, 
because  it  begins  to  pick  up  the  sheet  persistently.  When  this 
occurs  the  dandy  must  be  taken  off  and  cleaned.  The  right  way 
to  do  this  is  for  the  machine  tender  to  stand  at  the  front  end  of 
the  dandy  and  the  back  tender  at  the  back  end.  They  carefully 
lift  the  dandy  from  its  bearings,  and  if  this  is  done  quickly  and 


3o6  modern  pulp  AND  PAPER  MAKING 

skilfully  the  paper  will  not  be  broken.  Then  the  machine  tender 
up-ends  the  dandy  and  places  it  on  a  pair  of  supports  on  the 
floor  convenient  to  the  machine.  The  roll  is  now  scrubbed  with 
dilute  vitriol  (sulphuric  acid)  care  being  taken  that  this  acid 
is  not  too  strong.  A  little  acid  should  be  added  to  water  in  a 
pail.  It  can  then  be  tasted  by  sticking  one’s  finger  in  it,  and  if  it 
tastes  about  as  sour  as  lemon  juice  it  is  all  right  to  use.  The  acid 
is  applied  with  a  wire  scrubbing  brush  in  a  thorough  but  careful 
manner.  Finally,  the  dandy  roll  is  thoroughly  washed  off  with 


Courtesy:  The  Piisey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  I2I. — Couch  roll  portion  of  Fourdrinier  machine  showing  details  of 
housing  and  adjustment  by  means  of  geared  bevel  and  hand  wheels. 
This  illustration  shows  the  old  style  of  “plain”  guard-board. 

clean  water.  A  steam  hose  is  sometimes  of  benefit  in  cleaning  a 
dandy  roll. 

When  clean,  the  dandy  is  replaced  in  the  same  manner  as  when 
it  was  removed,  care  being  taken  to  give  it  a  little  twirl  in  the  di¬ 
rection  of  the  movement  of  the  wire  when  it  is  placed  in  the  jour¬ 
nals,  and  if  this  is  done  properly  the  paper  will  not  be  broken. 
Of  course,  it  is  always  advisable  to  see  that  the  dandy  is  clean 
before  starting  the  machine,  but  if  it  becomes  dirty  while  running 
the  cleaning  can  be  carried  out  in  the  above  manner  in  about 
fifteen  minutes. 

Couch  Rolls. 

As  the  web  of  paper  is  carried  with  the  wire  after  passing 
over  the  suction  boxes,  it  passes  between  couch  rolls  where  it  is 
further  squeezed  to  take  out  more  water.  The  bottom  couch  roll 


THE  MACHINE  ROOM 


307 


IS  made  of  brass  carefully  ground  to  a  smooth  and  true  surface. 
The  top  couch  roll  is  made  of  the  same  material  but  is  supplied 
with  a  seamless  tube  made  of  wool  called  a  jacket.  A  large 
amount  of  pressure  is  put  on  top  of  the  couch  roll  by  means  of 
levers  and  weights.  This  jacket  is  put  on  dry,  sewed  around 
(generally  with  sisal  cord)  at  the  ends  and  shrunken  in  with  hot 
water.  The  shrinking  should  be  begun  in  the  center  working  to¬ 
ward  each  end. 

The  bottom  roll  is  connected  with  a  clutch  to  a  driving  cone 
and  serves  to  drive  the  entire  Fourdrinier  part. 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  122. — Couch  roll  showing  Gately  patent  spring  guard-board. 

The  top  roll  contains  numerous  perforations  through  the  shell 
which  serve  to  let  out  any  water,  stock  that  may  press  through 
the  jacket,  and  lint  from  the  inside  of  the  jacket  which  would 
otherwise  create  lumps  which  would  be  very  harmful  because  of 
the  pinching  effect  on  the  paper.  These  lumps  would  also  be  an 
obstruction  to  the  guard-board  lip  as  the  roll  revolves. 

Guard-Board:  The  Guard-board  is  made  from  a  heavy  cypress 
or  hard  pine  plank  from  18  to  24  inches  wide  and  4  inches  thick 
and  trussed  on  the  back  side — also  over  the  top.  It  is  supported 
at  each  end  by  brackets  extending  from  the  upper  couch  roll 
housing.  It  bears  a  maple  lip  about  one  inch  thick  beveled  down 
to  about  inch  on  the  lower  edge.  This  lip  is  attached  to  the 
guard-board  with  iron  brackets.  Springs  are  provided  between 
the  lip  and  the  brackets  allowing  for  some  up  and  down  motion. 
This  lip  presses  on  the  couch  roll  jacket  at  such  an  angle  as  to 
press  out  moisture  and  retard  any  pulp  or  particle  of  dirt,  but 
not  at  such  an  angle  as  to  chatter.  Immediately  in  front  of  the 


3o8  modern  pulp  AND  PAPER  MAKING 

guard-board  lip  is  a  shower-pipe  extending  across  the  couch  roll 
to  facilitate  the  removal  of  pulp  and  dirt,  keeping  the  jacket  clean. 
The  lip  touches  the  roll  at  a  point  back  of  the  center  making  a 
shelf  for  water  to  rest  in.  Just  in  front  of  this  shelf  is  a  wiper 
consisting  of  a  strip  of  felt  hanging  from  a  wooden  bar  extending 
right  across  the  roll.  This  wiper  assists  in  the  maintenance  of  the 
pond  of  water. 

Couch  Roll  Jacket:  Either  through  faulty  construction,  pull¬ 
ing,  shrinking  or  stretching,  the  couch  roll  jacket  will  sometimes 
give  poor  service  in  several  different  ways. 

The  most  common  of  these  troubles  is  for  the  jacket  to  stretch 
in  the  center,  owing  to  the  center  constantly  traveling  faster  than 
the  two  ends  because  of  the  slight  crowning  of  the  bottom  roll. 

If  faults  of  this  kind  develop  it  does  not  necessarily  indicate 
that  the  jacket  is  of  faulty  manufacture.  The  best  possible 
jackets  can  give  poor  results  if  the  weights  on  the  couch  roll  are 
not  kept  even  at  the  two  ends,  if  the  guard-board  presses  un¬ 
evenly  or  for  many  other  reasons. 

If  the  jacket  should  stretch  in  the  center,  the  slack  will  gen¬ 
erally  remain  in  one  position,  a  little  behind  where  the  upper  and 
lower  rolls  meet,  and  unless  the  slack  is  excessive  no  harm  will  be 
done.  If  the  slack  becomes  excessive,  the  machine  must  be  shut 
down  and  the  couch  roll  lifted,  just  as  if  a  new  jacket  was  to  be 
put  on,  and  then  the  jacket  pulled  forward  and  the  ends  re-sewed 
to  take  up  the  slack. 

It  should  be  noted  that  the  center  of  the  top  couch  roll  is  set 
back  from  4  to  8  inches  from  the  vertical  line  running  through 
the  center  of  the  lower  couch  roll.  This  is  so  the  wire,  and  con¬ 
sequently  the  paper  forming  on  it,  will  be  gently  squeezed  against 
the  roll  before  being  subjected  to  the  heavy  pressure  where  the 
two  rolls  meet.  It  the  film  of  pulp  in  water  were  suddenly  sub¬ 
jected  to  the  full  force  of  the  pinch  the  paper  would  be  “curdled” 
or  “crushed”  and  the  forming  of  the  sheet  interrupted.  More¬ 
over,  this  arrangement  gives  a  straight  fall-away  for  the  water 
squeezed  out  by  the  rolls  which  would  have  to  run  around  the 
circumference  of  the  lower  roll  if  their  centers  were  set  in  a 
straight  line. 

Press  Rolls. 

The  first  press  comes  next  to  the  couch  rolls.  The  bottom 
rolls  are  made  of  iron  covered  with  an  inch  of  rubber,  the 
surface  being  ground  perfectly  round  and  true  and  slightly 
crowned.  On  top  of  these  rest  wooden  rolls  from  24  to  30 
inches  in  diameter.  Between  these  rolls  runs  an  endless  woolen 
felt  (sometimes  known  as  a  wet  felt  to  distinguish  it  from 
dryer  felts  that  will  be  dealt  with  later  on)  which  runs  over  a  sys¬ 
tem  of  supported  rolls  and  a  stretch  roll  to  keep  it  taut.  The 
web  of  paper  is  taken  off  the  couch  roll,  and  much  of  the  water 
is  taken  out  by  squeezing  through  this  massive  wringer. 


THE  MACHINE  ROOM 


309 


Press  rolls  are  very  essential  indeed.  The  web  of  paper  runs 
through  each  set  of  these  rolls  and  the  top  roll  is  connected  upon 
each  journal  with  compound  levers.  On  these  levers  are  heavy 
weights  and,  as  the  rolls  are  naturally  springy,  there  has  to  be 
sufficient  crown  put  on  them  to  offset  the  spring  so  that  every 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  123. — Press  part  of .  Fourdrinier  machine  showing  swinging-arm  type 
of  press  roll  housing.  In  order  to  show  the  construction  of  the 
press  part  it  is  illustrated  with  the  felt  removed. 

portion  of  the  surface  that  comes  in  contact  with  the  sheet  will  be 
perfect. 

There  are  several  reasons  for  the  crowning  of  press  rolls,  the 
most  important  of  which  is  the  necessity  of  weighting  the  ends 
of  the  rolls  with  heavy  weights.  This  in  itself  would  cause  the 
rolls  to  pinch  on  the  ends,  thereby  pressing  more  water  from  the 
paper  at  this  point  than  in  the  center  of  the  rolls.  To  avoid  this 
the  bottom  roll  is  ground  with  a  crown  or,  in  other  words,  it  is  of 
larger  diameter  in  the  middle  with  a  gradual  tapering  toward 


310  MODERN  PULP  AND  PAPER  MAKING 

the  ends.  Then  again,  supposing  no  weight  were  used  on  the 
ends  of  the  press  rolls,  and  the  rolls  were  finished  perfectly 
straight,  resulting  in  an  even  amount  of  water  being  pressed  from 
the  sheet  at  all  points.  Now  take  the  paper  over  the  dryers  and 
by  drying  soft  you  will  find  the  edges  of  the  paper  dry  and  the 
middle  part  wet.  This  is  caused  by  the  dryer  being  hotter  on  the 
ends  than  in  the  middle,  this  condition  being  due  to  the  deckles 


Courtesy:  The  Puscj  and  Jones  Co.,  Wilmington,  Del. 

Fig.  124. — Press  part  of  Fourdrinier  machine  showing  bell-crank  type  of 
housing.  The  equipment  is  illustrated  with  the  felt  removed  so  as 
to  better  show  the  construction  and  arrangement  of  the  rolls  and 
housing. 

which  do  not  entirely  cover  the  face  of  the  dryers,  thereby  leav¬ 
ing  an  uncovered  space  at  each  end  on  which  the  heat  is  un¬ 
checked.  You,  therefore,  must  go  back  and  put  a  crown  on  the 
press  rolls  to  overcome  this  difficulty.  There  are  no  definite 
standardized  formulas  which  give  the  proper  amount  of  crowning 
for  the  rolls.  This  is  determined  by  experience  only — by  flexi¬ 
bility  of  the  rolls — the  width — the.  hardness  of  the  rubber — the 
peculiarities  of  the  machine  as  a  whole.  The  metal  rolls  require 
less  crown  than  rubber  because  they  have  less  given  to  them. 
There  are  some  machines  which  have  peculiar  traces  such  as 


THE  MACHINE  ROOM 


311 

uneven  temperatures  on  the  face  of  the  dryers,  formation  of 
sheet,  removal  of  water  by  vacuum  system,  which  must  be  met 
and  overcome  by  crowning  the  press  rolls.  As  a  general  rule 
the  first  press  should  have  about  lo/iooo  of  an  inch  (in  cir¬ 
cumference)  more  crown  than  the  second  press.  The  only  real 
way  to  ascertain  the  proper  crown  for  the  roll  is  by  observing  the 
sheet  of  paper  when  it  is  just  a  trifle  on  the  damp  side.  If  the 
middle  of  the  sheet  shows  up  damper  than  the  edges,  then  the 
press  rolls  need  more  crowning,  provided  you  are  making  an 
even  level  sheet  on  the  wire.  If  the  edges  are  damp  and  the 
middle  dry  then  you  have  too  much  crown  on  the  roll.  When 
making  such  observations  be  sure  that  the  presses  are  set  evenly 
on  both  sides  and  have  the  levers  all  in  same  position. 

The  second  press  is  the  same  as  the  first,  and  also  the  third. 
Paper  should  leave  the  third  press  about  35  per  cent  dry,  and 
more  than  that  if  possible.  Even  then  this  leaves  65  per  cent  of 
the  total  tonnage  of  water  necessary  to  evaporate  in  the  sheet. 

Suction  boxes  similar  to  those  beneath  the  wire  are  placed 
under  the  felt,  just  in  front  of  the  pinch  of  the  press  rolls  so  the 
sheet  gets  the  benefit  of  the  suction  just  before  it  passes  through 
the  final  squeezing  of  the  press  rolls.  These  suction  boxes  also 
prevent  the  paper  from  “blowing”  which  is  the  paper-makers’ 
term  for  air  getting  between  the  felt  and  the  paper  and  forming 
wet  wrinkles  when  squeezed  out  by  the  press  rolls.  The  suction 
boxes  guard  against  this  by  removing  the  air.  They  also  keep 
the  felt  clean,  sucking  out  excess  water. 

The  top  roll  of  the  first  press  is  sometimes  offset  from  3  to  4 
inches  for  the  same  reason  that  the  upper  couch  roll  is  (see  page 
308).  It  is  also  desirable  to  have  the  top  wooden  rolls  a  little 
longer  than  the  bottom  rolls  to  prevent  the  edges  of  the  felt  from 
curling.  Each  top  wooden  press  roll  is  provided  with  a  doctor- 
blade  either  of  gutta  percha  or  of  maple  wood,  and  even  this  is 
usually  protected  from  direct  contact  with  the  roll  by  pieces  of 
wool  felt  under  the  edge. 

Suction  Rolls. 

Suction  rolls  are  specially  designed  rolls  to  take  the  place  of 
the  couch  roll  or  one  of  the  press  rolls,  and  which  are  intended 
to  rernove  water  from  the  paper  by  suction  in  the  same  manner 
as  it  is  removed  by  the  suction  boxes,  at  the  same  time  these 
rolls  performing  the  usual  functions  of  an  ordinary  couch  or 
press  roll.  With  the  operation  of  wider  and  faster  paper  ma¬ 
chines  great  interest  has  arisen  in  these  rolls  and  many  modern 
paper  machines  are  equipped  with  them. 

Since  modern  paper  machines  operate  at  very  high  speeds  it 
is  necessary  that  the  water  should  be  taken  from  the  paper  very 
rapidly  and  very  efficiently,  and  paper  machine  designers  have 
sought  to  improve  on  the  older  types  of  machine  which  depended 
for  the  removal  of  water  on  the  drainage  through  the  wire,  the 


I 


312  MODERN  PULP  AND  PAPER  MAKING 

action  of  the  suction  boxes  and  the  mechanical  pressure  of  the 
couch  and  press  rolls.  Moreover,  the  removal  of  the  water  must 
be  done  carefully;  there  is  a  limit  to  the  force  that  can  be  ex¬ 
erted  by  the  couch  and  press  rolls  without  breaking  or  crushing 

the  newly  formed  web  of  paper. 

In  the  ordinary  couch  roll  the  pressure  is  exerted  on  the  line 
where  the  top  roll  comes  in  contact  with  the  bottom  roll,  giving  a 
very  high  pressure  at  any  particular  point  in  this  area  of  con¬ 
tact.  As  the  water  is  squeezed  out  of  the  paper  at  this  point 
there  is  bound  to  be  some  disarrangement  of  tbe  fibres  of  the  pa¬ 
per  When  this  effect  becomes  excessive  it  is  the  cause  of  crush 
marks,  felt  marks,  etc.  The  suction  roll  pressure  is  distributed 


Courtesy:  Sandusky  Foundry  &  Machine  Co.,  Sandusky,  O. 


Fig.  125. — Diagram  showing  construction  and  operation  of  suction  couch 

and  press  rolls. 


over  a  much  greater  area,  that  area  being  the  whole  surface  of 
the  roll. 

“The  stationary  suction  chamber  (B)  is  connected  to  a  power¬ 
ful  rotary  vacuum  pump,  usually  located  in  the  basement  and 
driven  from  the  constant  speed  line.  The  contact  between  the 
suction  chamber  and  the  inside  surface  of  the  revolving  shell  (A) 
is  made  with  special  hydraulic  packing.  A  deckle  arrangement  is 
provided  for  adjusting  the  length  of  the  suction  area  to  accommo¬ 
date  any  width  of  sheet  made  on  the  machine.” 

“The  suction  couch  roll  eliminates  entirely  the  use  of  the  old 
top  couch  roll  with  its  felt  jacket  and  guard  board,  both  of  which 
require  constant  attention  and  are  responsible  for  many  of  the 
machine  tender’s  troubles,  such  as  crushing,  wet  streaks,  wire 
marking,  pick-ups,  accidents  to  wires,  etc.  The  suction  couch 
roll  does  not  displace  all  of  the  regular  flat  suction  boxes  on 
the  wire.  In  many  cases  the  number  of  flat  suction  boxes 
used  may  be  reduced,  or  what  is  equivalent,  the  degree  of  vacuum 
carried  on  them  lessened.  The  degree  of  vacuum  that  may  be 
maintained  at  the  suction  couch  roll  in  operation  largely  depends 
upon  the  weight  and  character  of  the  paper  made.  Likewise  the 


Courtesy:  Sandusky  Foundry  &  Machine  Co.,  Sandusky,  O. 


Fig.  126. — Suction  couch  roll  on  Fourdrinier  machine. 


Courtesy:  Sandusky  Foundry  &  Machine  Co.,  Sandusky,  O. 

Fig.  127. — Suction  press  roll  on  Fourdrinier  machine. 


313 


Courtesy :  Sandusky  Foundry  &•  Machine  Co,,  Sandusky,  O. 

Fig.  128. — Suction,  couch  and  press  rolls  on  Fourdrinier  machine. 


Courtesy:  Sandusky  Foundry  &  Machine  Co.,  Sandusky,  O. 

Fig.  129.— Suction  Roll  installed  on  cylinder  machine  making  boards. 


314 


y  THE  MACHINE  ROOM  315 

percentage  of  water  that  may  be  removed  by  the  couch  roll  also 
varies,  but  to_a  larger  extent  this  is  proportional  to  the  degree  of 
hydration  which  the  stock  undergoes  in  its  preparatory  treatment. 
This  accounts  for  the  fact  that  on  extremely  slow  stocks  like 
grease-proof  and  glassine,  the  paper  may  be  delivered  from  the 
suction  couch  roll  as  much  as  2^  per  cent  bone  dry,  whereas 
with  quickly  beaten  stocks  like  news,  the  amount  of  water  taken 
out  may  not  quite  equal  or  at  least  exceed  that  possible  to  take 
out  with  top  and  bottom  couch  rolls.  On  such  papers,  made 
from  the  _  free  stocks,  the  suction  couch  roll  must  be  kipple- 
mented  with  the  suction  press  roll  in  order  to  effect  increased  dry¬ 
ness  in  the  paper.”  ^ 

The  use  of  suction  rolls  admits  of  widely  varying  weights  of 
paper  being  made  on  the  same  machine.  There  seems  to  be  no 
limit  in  the  direction  of  heaviness  to  the  papers  which  can  be 
made  on  suction  roll  equipped  machines,  some  very  heavy  boards 
being  made  in  this  way ;  but  it  cannot  be  used  for  very  thin  tis¬ 
sues  and  cigarette  papers.  It  has  been  advanced  by  some  paper 
makers  that  the  suction  couch  roll  would  tend  to  remove  filler 
frpm  the  paper,  but  this  has  never  proved  a  serious  difficulty  in 
mills  where  the  device  is  in  constant  use. 

d  he  suction  press  roll  is  quite  similar  to  the  suction  couch 
roll,  except  that  it  is  surmounted  by  the  usual  top  press  roll.  The 
suction  press  roll  is  usually  inserted  in  the  first  press.  In  addi¬ 
tion  to  assisting  in  the  removal  of  water  from  the  sheet,  it  pre¬ 
vents  the  paper  from  sticking  to  the  top  press  roll,  a  difficulty  fre¬ 
quently  encountered,  because  of  the  positive  action  of  the  suction 
of  the  bottom  roll  which  holds  the  paper  to  it.  Moreover,  the  air 
passing  through  the  felt,  on  account  of  the  suction,  tends ’to  keep 
the  felt  open  and  clean,  lengthening  its  life. 

_  It  is  the  writer’s  opinion  that  the  chief  merit  of  suction  rolls 
IS  that  a  greatly  increased  degree  of  suction  can  be  obtained, 
without  adding  to  the  wearon  the  wire,  as  would  be  the  case  were 
this  suction  applied  with  flat  suction  boxes. 

The  first  cost  of  suction  lolls  is  a  large  item,  but  there  seem 
to  be  so  many  advantages  connected  with  their  use,  the  speed  of 
the  machine  can  be  increased  with  safety,  breaks  can  be  reduced, 
felts  made  to  give  longer  service,  etc.,  that  they  would  seem  to  be 
an  excellent  investment. 

Smoothing  Presses. 

Many  modern  paper  machines  are  equipped  with  smoothing 
presses.  This  device  is  not  strictly  a  press.  Its  function  is  not 
to  press  water  out  of  the  sheet,  which  is  the  purpose  of  the  true 
presses.  It  is  intended  to  smooth  and  flatten  the  sheet  after  it 
comes  from  the  presses  before  it  goes  to  the  dryers,  removing  all 
wire  and  felt  marks.  Many  such  marks  are  easier  removed  at 
this  stage  of  the  formation  of  the  sheet  than  later  after  the  paper 
has  dried. 


3i6  modern  pulp  AND  PAPER  MAKING 

The  upper  of  the  two  smoothing  rolls  is  covered  with  rubber, 
somewhat  softer  than  ordinarily  used  on  ordinary  press  rolls. 
The  lower  roll  is  provided  with  a  gun-metal  jacket  which  is 
ground  very  smooth.  This  roll  has  little  or  no  crown ;  the  upper 
roll  is  crowned  somewhat  more,  but  still  very  little. 

The  damp  web  of  paper,  usually  reversed  at  the  last  press, 
so  that  the  wire  marks  are  underneath,  is  led  over  and  around  the 
upper  rubber-covered  roll,  and  passes  between  it  and  the  gun 
metal  roll  underneath,  whence  it  passes  to  the  first  dryer.  The 
passing  of  the  paper  around  the  greater  part  of  the  upper  roll 
tends  to  make  the  pull  on  the  paper  stronger  in  the  middle  than  on 
the  edges,  thus  avoiding  tearing  of  the  sheet. 


Courtesy :  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  130. — Smoothing  press. 

The  success  of  the  smoothing  rolls  is  largely  dependent  on  the 
care  with  which  the  upper  roll  is  made.  Exactly  the  right  density 
or  hardness  is  necessary  if  the  perfect  smoothing  action  is  to  be 
obtained.  It  is  also  very  important  that  the  smoothing  action  of 
the  press  should  be  uniform  across  the  whole  width  of  the  sheet. 

The  smoothing  press  increases  the  strength  of  the  paper  due 
to  the  fact  that  it  is  smoothed  before  entering  the  dryers.  It 
smooths  the  fibres  in  the  sheet,  thus  allowing  closer  contact  with 
the  surface  of  the  dryers,  eliminating  air-spaces  hptween  paper 
and  dryer,  and  thereby  enabling  the  paper  to  be  dried  better  with 
the  same  amount  of  drying  surface,  or  with  a  lower  temperature 
in  the  dryers,  which  is  beneficial  to  the  paper.  It  yields  a  paper 
requiring  less  calendering  and  one  which  retains  its  finish  better 
when  glazed  on  the  calenders  only.  Such  a  finish  is  not  affected 
by  the  atmosphere.  It  obliterates  all  wire  and  felt  marks  at  the 
moment  when  the  sheet  is  most  sensitive  to  mechanical  finish. 


THE  MACHINE  ROOM  317 

Smoothing  pi  esses  a.ie  chiefly  useful  111  connection  with  the 
manufacture  of  good  book  and  writing  papers  at  moderate  speeds. 
They  are  also  useful  in  the  manufacture  of  blottings  and  some 
specialities  such  as  vegetable  parchment. 


Fig.  131.— Diagram  showing  method  of  installation  of  smoothing  press. 


Wet  Felts. 

The  process  of  making  paper-makers’  felts,  so  far  as  the 
technical  operations  are  concerned,  is  very  much  the  same  as  that 
of  making  any  woven  woolen  cloth,  especially  bed  blankets.  A 
paper-makers’  felt  is  in  reality  a  blanket  and  not  a  felt  in  the 
strict  sense  of  the  term,  the  latter  being  a  sheet  of  wool  fibre  so 
felted  or  pressed  together  as  to  present  a  smooth  surface  but  hav¬ 
ing  no  threads. 

In  making  paper-makers’  felt  long,  staple,  strong  wool  is 
carded  and  spun  into  two  kinds  of  yarns — the  first  being  used 
for  warp  or  threads  lengthwise  of  the  felt  and  the  second  for 
the  filling  or  cross  threads.  The  warp  gives  the  strength  and 
necessary  pulling  qualities  lengthwise.  The  filling  makes  the 
surface  of  the  felt  and  from  these  filling  threads  the  nap  is 
raised. 

.  The  seam  of  the  felt  is  made  by  hand.  A  long  fringe  of  warp 
is  left  on  each  end  when  the  piece  of  cloth  is  woven.  The  felt 
being  placed  on  a  table  with  the  two  ends  together,  the  joiner  ties 
a  knot  in  the  ends  of  the  two  exactly  opposite  threads  and  draws 
one  out ;  the  other  following  is  drawn  in  and  takes  its  place. 
I  his  operation  being  repeated  first  on  one  side  and  then  on  the 
other  makes  a  perfect  hand-woven  seam. 

u  fulling  or  thickening  of  the  cloth  then  takes  place 

and  finally  the  raising  of  the  nap.  The  coarseness  of  the  yams, 


3i8  modern  pulp  AND  PAPER  MAKING 

as  well  as  of  the  wool,  varies  with  the  kind  of  paper  to  be  made. 

The  writer  does  not  know  who  first  discovered  the  use  of 
woolen  blankets  as  related  to  paper  making,  but  for  a  great  many 
years  they  have  played  an  important  part,  not  only  in  machine- 
made  paper,  but  in  hand-made  paper  as  well. 

The  wool  fibre  among  all  textiles  is  the  only  one  against  which 
a  wet  sheet  of  paper  may  be  pressed  to  remove  the  water  and 
from  which  this  water  may  again  be  removed  by  pressure.  It  is 
the  only  fibrous  material  which  will  pick  up  a  sheet  of  wet  paper 
from  some  other  carrying  medium  and  deliver  it  again  to  any  de¬ 
sired  point  without  injuring  the  sheet  and  with  no  particles  of  the 
paper  stock  adhering  to  it. 

At  first  the  two  ends  of  a  piece  of  felt  were  carefully  sewed  to¬ 
gether  to  make  the  carrying  belt  for  a  paper  machine ;  later  the 
possibility  of  weaving  the  seam  by  hand  and  so  joining  the  two 
ends  to  make  a  perfect  endless  belt,  was  realized,  and  on  this  as 
much  as  on  the  endless  Fourdrinier  wire,  modern  paper  making 
depends. 

Felts  are  of  almost  as  many  varieties  as  there  are  kinds  of  pa¬ 
per  made ;  but,  as  a  basis,  it  may  be  said  that  they  are  all  made 
of  strong  fibered  wools,  varying  in  coarseness  with  the  paper  to 
be  made.  The  main  object  to  be  gained  is  a  felt  of  the  greatest 
possible  strength  and  resistance  to  friction,  together  with  a  texture 
so  loose  as  to  admit  of  maximum  removal  of  water  from  the  sheet 
of  paper.  Serving  as  a  belt  or  carrying  apron,  it  must  be  smooth 
and  even  in  surface ;  must  run  straight  and  true ;  the  edges  must 
be  firm  and  it  must  hold  the  desired  width  while  running  day 
after  day  under  the  varying  conditions  on  the  paper  machine. 
It  must  be  remembered  that  one  of  the  chief  characteristics  of 
wool  fibre  is  that  it  shrinks  or  felts  together.  This  felting  or 
fulling  must  be  so  supplied  to  the  paper  felt  that  it  will  not 
shr.ink  more  after  being  put  on  the  machine. 

Most  felts  which  are  used  for  finer  papers  have  a  nap  to  pre¬ 
vent  the  paper  from  being  pressed  against  the  threads  and  thus 
an  impression  in  the  paper  being  formed. 

On  the  earlier  types  of  machines,  which  were  narrow  and 
ran  at  slow  speeds,  there  were  only  two  presses.  The  first  press 
of  about  24  feet  in  length  and  a  second  press  usually  12  feet 
in  length.  With  the  development  of  the  Fourdrinier  machine, 
extra  width  was  added  and  speeds  increased  and  it  was  found 
desirable  to  have  both  first  and  second  press  felts  much  longer, 
and  finally,  a  third  press,  and  in  some  cases  a  fourth,  was 
added. 

The  invention  of  the  Harper  Fourdrinier  machine  also  neces¬ 
sitated  the  use  of  very  long  felts,  and  as  cylinder  machines 
became  adapted  to  the  making  of  heavy  boards  and  papers 
the  felts  were  increased  in  length  to  take  the  paper  from  the 
additional  cylinders. 

While,  as  has  been  said,  a  woolen  felt  will  carry  the  sheet 


THE  MACHINE  ROOM 


319 


of  wet  paper  without  the  paper  stock  adhering  to  it,  a  certain 
amount  of  the  stock,  or  of  the  filler  run  with  the  paper,  is 
gradually  taken  up  by  the  felt,  necessitating  washing  either 
with  a  shower  of  water  constantly  pouring  on  the  felt  at  a 
point  where  the  felt  may  also  be  freed  by  being  beaten  with  a 
driven  cylinder  with  blades,  or  by  shutting  the  machine  down  and 
removing  the  felt,  or  by  washing  on  the  machine  by  the  method 
described  later. 

Another  addition  to  the  modern  machine  which  has  helped 
felts  materially  is  the  suction  box.  This  helps  to  remove  the 
water  and  to  dry  the  paper,  and  without  it  the  fast  speed  of  the 
modern  Fourdrinier  machine  would  be  impossible.  There  is  much 
difference  of  opinion  as  to  whether  a  suction  box  made  of  a  plate 
with  round  perforations,  or  one  with  long  slits  with  rounded 
edges,  causes  less  wear  on  the  felts  through  friction.  The  felts 
are  finally  worn  out  by  friction  and  by  the  action  of  the  water 
in  which  they  are  constantly  run ;  the  water  must  of  necessity 
finally  rot  the  woolen  fibre.  This  is  consequently  a  fixed  con¬ 
dition  so  that  the  life  of  a  felt  depends  very  largely  on  the 
amount  of  friction  to  which  it  is  subjected.  This  friction  comes 
not  only  from  the  suction  boxes  but  from  the  felt  carrying  rolls 
and  from  the  presses  through  which  the  felt  runs.  The  old- 
fashioned,  iron  bottom  press  rolls  have  been  superseded  by  rolls 
covered  with  soft  rubber.  This  one  fact  has  caused  the  saving 
of  an  immense  amount  of  money  to  paper  manufacturers.  The 
best  practice  today  is  to  cover  the  bottom  press  roll  with  a 
coating  of  from  ^  to  i  inch  of  a  comparatively  soft  rubber 
composition.  As  the  roll  wears  and  becomes  uneven  it  should 
be  turned  down  again ;  it  is  false  economy  to  run  rolls  on 
which  the  rubber  has  worn  down  so  thin  and  become  so  scored 
by  wear  that  the  friction  on  parts  of  the  felt  is  very  much  in¬ 
creased. 

The  second  cause  of  friction,  which  always  materially  shortens 
the  life  of  felts,  is  the  felt  carrying  rolls.  Wooden  rolls  will  not 
keep  their  shape  in  the  extreme  lengths  of  the  modern  ma¬ 
chine  and  iron  rolls,  whether  galvanized  or  not,  soon  become 
rusty  and  pitted  so  that  even  the  small  friction  necessary  to 
pull  them  creates  a  grinding  effect  on  the  surface  of  the  felt 
which  soon  removes  the  fibre  and  injures  the  fabric.  Many 
experiments  have  been  made  toward  obtaining  rustless  felt 
rolls  but  the  best  modern  practice  is  to  have  the  rolls  covered 
with  brass. 

In  size,  felts  on  the  modern  machine  have  gradually  in¬ 
creased  to  lengths  of  forty,  fifty  and  sixty  feet.  Here  also, 
there  is  a  great  difference  of  opinion,  but  at  the  present  time 
the  majority  of  Fourdrinier  machines  are  being  built  for  first 
press  felts  varying  in  length  from  forty  to  sixty  feet — the 
second  and  third  press  felts  a  little  shorter  in  some  cases  than 
the  first. 


320 


MODERN  PULP  AND  PAPER  MAKING 


As  has  been, said,  the  quality  of  felts  used,  varies  with  the 
paper  to  be  made.  Different  paper  makers  (and  in  fact  felt 
makers  as  well),  have  varying  ideas  as  to  the  exact  quality  re¬ 
quired  for  each  particular  kind  of  paper,  but  in  general  the 
following  statement  might  be  made. 

For  Fourdrinier  machines  the  felts  must  vary  in  quality  de¬ 
pending  on  whether  the  paper  to  be  run  is  news,  manila,  book, 
writing,  etc.  All  must  have  the  quality  of  openness  and  free 
running  and  must  be  capable  of  running  the  longest  possible 
time  without  washing,  which  is  usually  done  by  relieving  the 
pressure  on  the  press  rolls  and  guiding  the  felt  into  the  center 
until  it  forms  a  long  rope  which  is  pressed  between  the  rolls 
as  the  machine  runs  slowly. 

The  felt  on  the  second  press  is  sometimes  of  the  same  quality 
as  that  on  the  first,  but  usually  heavier,  while  third  press  felts 
are  still  heavier.  The  relative  length  of  service  of  the  first, 
second  and  third  press  felts  on  fast  running  machines  seems 
to  depend  on  the  amount  of  work  in  drying  the  paper  that  each 
is  made  to  do.  In  other  words,  the  heavier  the  pressure  on  the 
felt  and  the  heavier  the  suction,  the  shorter  its  life.  Neces¬ 
sarily  with  the  great  increases  of  speed  met  with  in  modern 
Fourdrinier  machine  operation,  the  service  required  of  felts 
has  become  much  more  severe.  At  the  present  time  a  great 
strain  must  be  put  on  the  felts  lengthwise — in  other  words  they 
must  be  run  very  tight — to  keep  them  open,  and  admit  of  the 
high  speed. 

For  tissue  paper  very  fine  felts  with  no  nap  are  required 
and  owing  to  the  peculiar  conditions  on  tissue  machines,  the 
thinness  of  the  paper  and  the  necessary  thinness  of  the  felt,  as 
well  as  the  fact  that  felts  become  filled  with  stock  very  quickly 
and  require  constant  hard  beating,  the  felts  probably  cause  more 
trouble  on  these  machines  than  any  other. 

Harper  Fourdrinier  machines  require  felts  somewhat  stronger, 
the  same  in  general  character  as  Fourdrinier  machines  running 
the  same  grades  of  paper. 

Large  cylinder  machines  running  board  on  several  cylinders, 
if  the  board  is  to  be  of  high  finish,  require  felts  of  great  longi¬ 
tudinal  strength  to  carry  the  strain  of  the  cylinders  and  squeeze 
rolls  and  yet  of  sufficiently  fine  warp  to  give  the  required  finish 
to  the  board. 

Wet  machines  running  pulp  (for  these  also  require  carrying 
felts),  should  have  very  strong,  coarse  felts,  thicker  and  heavier, 
with  looser  weave  in  the  case  of  sulphite;  closer  and  firmer,  but 
still  strong  and  open,  in  the  case  of  ground  wood. 

These  varying  conditions,  and  this  increasing  severity  of 
service,  have  presented  a  great  problem  to  the  felt  manufacturer. 
He  has  constantly  been  obliged  to  change  his  felts  to  meet  new 
and  changing  conditions  and  in  many  cases  he  has  not  been  in¬ 
formed  of  contemplated  changes  until  the  felts  he  has  been 


THE  MACHINE  ROOM 


321 


supplying  have  been  blamed  for  not  meeting  conditions,  for 
which  they  were  not  designed,  and  of  which  he  had  not  been 
informed. 

The  life  of  a  felt  depends  very  largely  on  the  treatment 
it  receives  at  the  hands  of  the  machine  tenders.  To  meet  the 
conditions  under  which  it  is  used,  it  must  necessarily  be  a 
comparatively  delicate  woolen  fabric,  easily  torn  or  injured, 
and  yet  it  must  do  the  work  of  an  endless  belt  running  con¬ 
stantly  at  a  high  rate  of  speed  between  heavy  rolls,  carrying  a 
great  weight  of  paper  and  water,  and  with  constant  liability 
to  injury  from  unforeseen  causes.  There  is  no  point  in  paper 
making  where  care  and  watchfulness  count  for  more  than  in 
the  treatment  and  use  of  felts.  Felts  in  the  stock  room  should  be 
carefully  watched  and  kept  free  from  moths  by  the  application 
of  camphor,  naphthaline  or  tarred  paper;  they  should  be  kept 
free  from  all  dirt  and  grease.  The  room  should  be  dry  and  yet 
not  hot. 

Great  care  should  be  exercised  in  starting  felts  on  the 
machine,  since  many  felts  are  ruined  by  careless  starting, 
whereas  if  a  little  precaution  had  been  taken  they  could  be 
made  to  give  full  and  satisfactory  service.  The  amount  of 
service  that  can  be  obtained  from  a  felt  varies  so  greatly  with 
different  conditions  that  it  is  impossible  to  lay  down  any  rule 
for  this.  Felts  on  two  machines  running  side  by  side  will  some¬ 
times  differ  50  per  cent  or  more  in  the  amount  of  service  given 
and  the  amount  of  paper  made.  It  is  possible  for  a  felt  to  be 
injured  in  so  many  different  ways  that  the  felt  itself  should  not 
be  considered  defective  until  every  possible  source  of  damage 
on  or  about  the  machine  has  been  investigated  and,  in  case 
the  paper  maker  becomes  convinced  that  the  felt  is  defective 
in  some  way,  it  should  never  be  sold  or  destroyed,  but  should 
be  held  until  the  manufacturer  has  been  informed  of  the  sup¬ 
posed  defect.  Felt  manufacturers  invariably  make  it  a  rule 
that  felts  claimed  to  be  defective  must  be  returned  for  their 
inspection  and  this  rule  is  certainly  a  just  one. 

The  treatment  of  worn  out  felts  is  always  an  important  sub¬ 
ject  for  consideration  by  the  paper  maker.  In  most  paper  mak¬ 
ing  communities  there  is  a  demand  for  these  old  felts  for  use 
as  blankets  from  people  living  in  the  vicinity.  The  felts  should 
be  carefully  washed  and  cleaned,  put  in  as  attractive  shape  as 
possible  and  in  a  place  where  they  can  be  easily  inspected. 
Some  of  the  poorest  in  which  the  fibre  has  become  very  rotten 
and  threadbare  can  be  disposed  of  only  as  waste  material,  but  the 
heavy  second  and  third  press  felts,  and  all  felts  that  have  been 
taken  from  the  machine  because  they  have  been  damaged,  should 
be  sold  for  blanketing  at  prices  depending  on  the  quality.  This 
is  an  important  source  of  saving  to  the  paper  maker  and  the 
careful  handling  of  old  felts  may  mean  the  reduction  of  cost  by 
many  hundreds  of  dollars  in  a  large  mill. 


322  MODERN  PULP  AND  PAPER  MAKING 

Proper  Care  of  Felts. 

Felts  should  be  thoroughly  inspected  before  being  put  on 
paper  machines.  The  rolls,  boxes,  and  journals  should  be 
thoroughly  cleaned.  The  press  rolls  should  be  Ijfted  high 
enough  to  give  the  felt  plenty  of  clearance  for  passing  under 
the  roll.  All  felt  roll  journals  should  be  exercised  that  the 
sharp  ends  of  the  journal  do  not  cut  the  felt  when  passing 
through  it.  After  all  the  rolls  are  in  proper  place  and  before 
letting  down  the  press  rolls,  the  felt  should  be  straightened 
out  as  smoothly  as  possible,  and  in  proper  alignment  with  the 
machine.  The  top  press  roll  may  then  be  lowered  onto  the 
felt.  The  stretch  rolls  should  be  strained  up  only  tight  enough 
to  take  care  of  the  slack  in  the  felt.  There  should  be  a  man 
on  either  side  of  the  felt  and  in  front  of  the  press  rolls  to  pull 
out  any  wrinkles  that  may  pass  between  the  rolls  when  first 
starting  the  felt. 

Before  applying  any  water,  the  felt  should  be  run  around 
and  gradually  strained  up,  but  not  too  tight,  as  the  application 
of  the  water  causes  it  to  full  up,  or  shrink.  This  application 
must  be  very  carefully  done ;  one  should  never  permit  a  solid 
stream  from  the  hose,  to  be  used,  by  holding  it  over  one  point 
as  the  felt  runs  around,  causing  a  wet  streak  in  the  center, 
as  this ,  method  usually  results  in  spoiling  the  felt.  In  fact, 
such  methods  sometimes  causes  a  felt  to  run  in  a  straight 
wrinkle  its  whole  length,  caused  by  this  portion  of  the  felt 
fulling  up,  or  shrinking  in  the  streak  where  the  water  was  ap¬ 
plied.  The  only  proper  way  to  wet  down  a  new  felt  previous  to 
putting  on  the  web  of  paper,  is  to  apply  the  water  through 
a  shower  pipe,  preferably  across  the  full  length  of  a  roll,  so 
that  the  water  may  be  evenly  distributed  as  the  felt  runs  around ; 
the  object  being  to  give  the  felt  an  even  amount  of  moisture 
its  whole  width  so  that  when  it  passes  between  the  press  rolls, 
its  very  fiber  will  be  made  moist  and  it  will  thus  shrink  evenly. 

Proper  attention  should  be  given  to  the  seam  in  the  felt, 
that  it  may  run  as  nearly  straight  across  the  machine  as  is 
reasonably  possible.  It  will  be  found  that  presses  on  account 
of  the  many  rolls  they  contain,  no  matter  how  perfectly  con¬ 
structed,  during  a  large  number  of  revolutions  will  gradually 
lead  the  seam  ahead  or  allow  it  to  fall  behind  at  one  place  or 
another.  The  only  method  of  eliminating  this  trouble  is  to 
see  that  all  the  rolls  are  properly  turned  true  in  a  lathe ;  this 
includes  the  press  roll,  as  the  crowning  of  the  bottom  press 
roll  is  sure  to  run  the  seam  ahead  in  the  center  if  such  influence 
is  not  offset  by  the  balance  of  the  carrying  rolls. 

A  seam  that  runs  very  crooked  has  the  affect  of  pulling  the 
warp  in  certain  places  to  such  an  extent  as  to  close  up  the 
meshes  of  the  felt,  thus  allowing  it  to  be  filled  up  with  the  fine 
pulp  in  this  particular  streak,  and  finally,  to  mark  the  paper; 


THE  MACHINE  ROOM 


323 


this  produces  what  are  known  as  “crush  marks.”  The  run¬ 
ning  of  one  side  of  the  seam  ahead  of  the  other,  presenting  a 
diagonal  appearance  across  the  felt,  can  be  corrected  by  the 
stretch  roll.  This  should  be  attended  to,  as,  if  the  felt  is  left 
with  one  side  running  several  inches  ahead  of  the  other,  it  is 
very  difficult  to  guide  and  liable  to  run  into  wrinkles  and  thus 
be  injured. 

Tbe  cause  of  one  side  of  the  peam  travelling  ahead  of  the 
other  is  that  it  does  not  have  so  far  to  travel  around  the  cir¬ 
cumference  of  the  group  of  rolls  in  the  press;  hence  the  side 
of  the  seam  in  advance  should  be  strained  up  so  that  the  cir¬ 
cumference  will  be  increased. 

Stretch  roll  arrangements  are  so  constructed  that  the  front 
side  must  be  thrown  out  of  gear  in  order  to  increase  or  diminish 
the  circumference  of  one  side.  This  makes  it  possible  to  operate 
only  the  back  side  of  the  stretch  roll,  so  that  if  the  front  side 
of  the  felt  seam  is  running  ahead  of  the  back  side,  the  back  side 
of  the  stretch  roll  should  be  slacked  up  thereby  decreasing 
the  circumference,  allowing  the  back  side  of  the  felt  seam  to 
catch  up  to  the  front.  If  the  seam  runs  in  the  reverse  manner 
the  process  of  adjusting  should  be  reversed. 

There  is  such  a  difference  in  the  shrinkage  of  woolen  felts  that 
it  is  impossible  to  lay  down  any  rules  by  which  to  be  guided. 
It  is  usually  tbe  best  practice  to  always  use  one  kind,  of  felt, 
of  course,  being  sure  that  a  felt  is  chosen  that  is  best  adapted 
to  the  grade  of  paper  being  made. 

Some  felts  will  shrink  in  length  without  appearing  to  be¬ 
come  narrower  while  others  will  narrow  up  and  stretch  out 
in  length. 

Defects  in  the  manufacture  of  felts  are  troublesome  to  paper 
makers.  A  felt  often  gives  unsatisfactory  service  in  spite 
of  all  the  care  and  proper  treatment  that  can  be  given.  Many 
felts  develop  “bad  spots” — that  is,  spots  that  will  crush  the- 
paper,  varying  in  size  from  a  silver  dollar  to  five  or  six  inches 
in  diameter.  There  appears  to  be  a  slack  place  in  the  weaving, 
leaving  this  particular  place  more  closely  woven,  and  causing 
the  felt  to  “bag.”  Such  places  invariably  crush. 

The  writer  knows  of  no  cure  for  this,  and  such  a  felt 
should  be  condemned,  as  it  is  the  direct  fault  of  the  manu¬ 
facturer. 

Other  felts  develop  into  straight  wrinkles  in  spite  of  the 
usual  care  in  starting  them  when  new.  This  is  often,  though 
not  always,  due  to  their  manufacture;  but  it  can  be  stated  that 
if  proper  care  is  adhered  to  as  above  described  and  the  felt 
wrinkles  straight  around,  the  blame  can  be  placed  with  tbe 
manufacturer.  Such  felts  should  be  carefully  removed  from 
the  machine  and  put  in  safe  keeping,  subject  to  inspection  or 
investigation  by  the  felt  manufacturer. 

Many  felts  are  ruined  through  carelessness  of  machine  op 


324  -MODERN  PULP  AND  PAPER  MAKING 

erators.  It  is  not  an  uncommon  occurence  to  see  third  hands  or 
machine  helpers  when  picking  paper  from  the  first  press,  throw 
it  into  the  second  press  in  large  wads.  This  should  never 
be  done  as  it  always  results  in  injuring  the  felts  especially 
if  the  weights  are  left  on.  The  leaving  on  of  the  press  lever 
weights  when  putting  paper  on  the  felts  is  careless  negligence,  and 
should  not  be  permitted. 

Felts  should  be  supplied  with  automatic  guides  to  keep  them 
in  the  middle  of  the  machine  and  in  proper  alignment.  This  is 
especially  true  of  first,  or  wet  felts.  Second  press  felts  can 
usually  be  guided  by  means  of  a  hand  guide. 

Copper  tacks  commonly  used  around  the  paper  machines 
should  be  used  with  discretion,  as  one  of  them  will  ruin  a  felt 
in  short  order. 

Wooden  rolls  having  worming  or  listing  tacked  on  them, 
should  be  very  carefully  scrutinized  when  changing  felts  and 
tacks  liable  to  work  out  removed  or  driven  in. 

Felts  should  never  be  run  after  becoming  filled  up;  and 
under  no  consideration  should  the  help  be  allowed  to  scratch 
the  felt  with  wire  brushes  when  it  becomes  filled  up  as  this 
destroys  the  nap,  rendering  the  felt  unusable;  whereas,  if  a  felt 
in  this  condition  is  promptly  washed,  either  on  the  machine  or 
off,  its  life  can  be  extended  to  a  reasonable  length. 

The  abuses  mentioned  have  been  practiced  by  unscrupulous 
machine  help  to  aid  them  through  their  respective  tours  so 
that  the  work  of  washing  or  changing  would  fall  to  the  work¬ 
men  on  the  next  tour.  This  is  a  narrow  view  of  the  matter, 
as  such  a  method  of  procedure  is  detrimental  to  the  production 
of  the  machine  and  to  the  company. 

The  application  of  strong  acids  or  soda  ash  water  to  avoid 
washing  felts  thoroughly,  should  not  be  permitted.  If  the 
judgment  of  the  machine  help  could  be  depended  upon  absolutely 
that  they  would  never  apply  soda,  ash  water  strong  enough 
to  injure  the  fibers  of  the  felt,  the  judicious  use  of  a  small 
amount  might  be  permissible  under  certain  conditions ;  but  the 
ordinary  procedure  is  to  put  from  a  pint  to  a  quart  of  strong 
soda  ash  into  a  pail  of  water,  boil  this  by  means  of  a  hose, 
and  dump  it  upon  the  felt-grit,  settlings  and  all.  As  there 
is  sure  to  be  a  good  c[uantity  of  these,  soda  ash  if  used,  should 
be  strained  through  a  piece  of  fine  cloth  or  a  Fourdrinier  wire 
to  remove  the  gritty  material  after  it  is  dissolved. 

On  the  latest  modern  fast  news  machines  it  is  not  con¬ 
sidered  economy  to  spend  much  time  in  darning  holes  in  fells, 
as  in  only  unusual  cases  can  this  be  done  with  any  degree  of  ' 
saving.  If,  for  instance,  a  felt  should  become  torn  when  new, 
a  careful  and  expert  workman  can  often  close  the  break  with  a  - 

fine  cambric  needle  and  soft  silk  thread  so  that  it  will  run  * 

for  sometime  provided  such  breaks  are  not  allowed  to  run  •* 
until  the  edges  become  frayed  out. 


THE  MACHINE  ROOM 


325 

Soft  woolen  yarns,  however,  are  used  to  a  considerable 
extent  on  ground  wood  and  sulphite  wet  machine  felts  as  the 
imprint  of  the  mending  does  not  affect  the  quality  of  the  product. 
The  mending  of  a  felt  with  woolen  yarn  should  be  done  very 
similarly  to  the  darning  of  a  stocking — the  threads  should  be 
properly  crossed  at  the  right  intervals  imitating  the  weave  of 
the  felt  just  as  nearly  as  possible.  The  presence  of  knots  and 
other  hard  particles  of  yarn  should  be  avoided. 

Each  press  in  the  paper  machine  should  do  its  share  of  the 
work,  the  web  of  the  paper  never  being  allowed  to  pass  one 
press  without  its  proportional  share  of  the  water  being  taken  out 
at  this  point,  otherwise  the  second  press  levers  must  be  loaded 
down  to  make  up  for  what  the  first  press  did  not  accomplish. 
Presses  should  be  kept  in  proper  condition  to  allow  the  top 
press  roll  to  rise  and  fall  in  proportion  to  any  differences  in  the 
thickness  of  the  material  passing  between  it  and  the  bottom 
roll.  The  levers  should  never  be  allowed  to  bind  but  should  al¬ 
ways  remain  flexible. 

One  side  of  a  press  should  not  be  weighted  to  any  extent 
heavier  than  the  other.  It  sometimes  happens  that  a  little 
more  pressure,  is  necessary  on  one  side  to  dry  out  the  web  evenly. 
In  such  cases  it  will  usually  be  found  that  one  or  the  other 
of  the  press  rolls  needs  regrinding,  or  that  the  top  roll  is  not 
in  strict  alignment  with  the  bottom. 

Save-alls  under  presses,  and  spouts  leading  from  them  to  carry 
off  water  pressed  from  the  sheet,  should  be  kept  free,  so  that 
such  water  will  not  run  onto  the  felt.  This  would  soon  fill 
up  the  meshes  with  slime  and  cause  the  felt  to  crush.  In 
rinsing  up  the  machine  around  the  presses  care  must  be  taken 
not  to  rinse  grease  and  oil  onto  the  edge  of  the  felt. 

If  a  felt  becomes  bare  and  napless  from  the  fact  of  its 
having  been  in  service  for  a  considerable  time  on  one  side, 
it  may  be  turned  over,  thus  giving  the  benefit  of  the  other  side 
of  the  nap.  Felt  should  never  be  put  on  a.  machine  with  the  nap 
running  the  wrong  way — it  should  be  passed  through  the  rolls 
so  that  the  nap  will  be  smothered  down. 

Felts  speedily  become  worn  out  if  they  are  not  allowed  to 
dry  when  the  machine  is  shut  down.  This  is  one  of  the  reasons 
for  washing  of  felts  on  the  machine.  They  cannot  dry.  The 
mechanical  flaws  of  felts  are  very  numerous  and  one  of  these 
is  excessive  tension.  This  tension,  however,  can  be  helped  to 
a  marked  degree  by  proper  choice  of  bearings  and  lubrication 
for  the  various  sets  of  rolls. 

At  the  present  time  there  have  been  placed  upon  the  market 
automatic  felt  washers  which  make  it  possible  to  wash  the 
felts  without  the  customary  shut  downs,  and  also  give  the 
felts  an  increased  life.  One  of  these  machines  is  the  Bennett 
Felt  Cleanser.  The  washer  consists  of  two  rolls  and  steam 
pipes,  the  rolls  controlled  by  means  of  a  lever.  The  operation 


326  MODERN  PULP  AND  PAPER  MAKING 

is  of  the  simplest  nature.  Whenever  the  felts  are  to  be  washed 
steam  is  turned  on  and  the  steam  pipe  is  pressed  down  against 
the  felt.  In  a  few  seconds  the  felt  is  thoroughly  cleaned  of 
all  dirty  substances.  This  method)  is  thorough  and  avoids 
wrink'les  and  creases  so  common  to  the  present  hand  manipula¬ 
tion  of  felt  washing.  Moreover,  the  life  of  the  felts  are  greatly 
increased  and  old  felts  (which  under  the  old  system  seemed 
to  have  lost  all  their  nap),  when  submitted  to  this  washer  take 
on  a  new  life  with  the  reappearance  of  nap  that  seemed  to 
have  been  all  worn  off. 

Dryers. 

The  purpose  of  the  dryers  is  to  remove  by  means  of  heat 
the  65  per  cent  or  more  .of  water  still  left  in  the  paper  after 
it  has  passed  through  the  presses. 

The  dryer  consists  of  a  series  of  cast-iron  cylinders  usually 
erected  so  there  is  a  double  row  of  them,  one  on  top  of  the 
other,  and  geared  so  they  will  all  move  at  the  same  speed.  Heat 
is  supplied  by  steam  piped  into  these  cylinders ;  the  water  of 
condensation  is  removed  by  various  devices. 

The  dryer  cylinders  are  of  cast  iron,  turned  perfectly  true 
on  the  surface  and  polished.  The  most  ordinary  size  is  4 
feet  diameter.  The  castings  must  be  perfect,  as  the  presence 
of  flaws,  sand  holes  and  other  defects  often  found  in  large 
castings  is  dangerous,  there  often  being  a  considerable  pres¬ 
sure  exerted  on  the  dryers  to  provide  the  necessary  degree  of 
heat.  The  cylinders  should  be  bored  out  smoothly  so  that  the 
shell  is  of  a  uniform  thickness  throughout  its  circumference. 
Dryers  not  bored  in  this  manner  often  contain  considerably  more 
metal  on  one  side  than  on  the  other,  which  condition  causes 
them  to  be  out  of  balance  and  renders  necessary  the  bolting 
on  of  a  large  piece  of  metal  so  as  to  offset  the  extra  weight 
opposite.  Moreover,  varying  thickness  in  the  cylinder  causes 
variation  in  the  drying  effect,  owing  to  the  great  amount  of 
heat  necessary  to  bring  the  thicker  metal  up  to  the  same  tem¬ 
perature  as  the  thinner. 

Dryers  should  be  turned  on  the  outside  and  polished  as 
bright  and  smooth  as  possible.  The  presence  of  tool  marks 
or  blemishes  of  any  kind  is  fatal  to  the  finish  of  the  paper. 

Arrangement  of  Dryers:  The  most  usual  arrangement  of 
the  dryers  is  that  already  alluded  to,  viz.,  in  two  rows,  one 
above  the  other.  With  such  an  arrangement  each  tier  usually 
has  one  long  dryer  felt.  The  majority  of  dryers  in  America 
are  arranged  in  this  way. 

European  machine  builders  have  inclined  more  towards  sep¬ 
arating  the  dryers  into  two,  three  or  more  nests,  each  nest 
having  an  independent  dryer  felt.  This  permits  of  driving  the 
different  nests  of  dryers  at  slightly  different  speeds,  which  is 


THE  MACHINE  ROOM 


327 

sometimes  an  advantage  for  the  following  reasons:  The  dryers 
are  all  of  equal  diameter  and  connected  together  by  a  train  of 
gears  having  equal  numbers  of  teeth.  Therefore,  the  speeds 
of  the  surfaces  of  the  dryers  must  be  equal.  The  paper,  how¬ 
ever,  is  shortening  as  it  drys.  If  the  paper  were  to  slip  to  an 
equal  degree  on  all  the  dryers  this  shortening  would  be  of  no 
consequence  at  all,  but  since  the  condition  of  the  surfaces  of 
the  dryers  is  never  quite  the  same  for  all  of  them,  the  paper 
as  it  shortens,  slips  a  little  more  on  one  dryer  than  on  another 
and  is  thus  subjected  to  a  certain  amount  of  stretching.  It  is 
claimed  that  the  loss  of  strength  in  certain  fine  papers  due 
to  this  cause  sometimes  amounts  to  as  much  as  20  per  cent. 

Furthermore,  each  of  the  long  felts  comes  in  close  contact 
with  the  wet  paper  coming  from  the  presses  and  absorbs 
moisture,  which  shrinks  it  for  a  time.  In  shrinking  the  felt 
holds  the  paper  alternately  more  and  more  tightly  against  the  sur¬ 
face  of  the  dryers,  but  as  the  wet  paper  and  the  partly  wetted 
felts  move  on  through  the  dryers  they  dry  more  and  more,  the 
paper  tending  to  shrink  and  the  felt  tending  to  stretch  out. 

In  making  ordinary  grades  of  paper  these  disadvantages  in 
the  American  method  of  arranging  ylryers  do  not  become  of 
importance  and  machines  making  newsprint,  a  comparatively 
delicate  kind  of  paper,  run  at  very  high  speeds  without  breaks 
for  days  at  a  time. 

However,  the  European  practice  of  dividing  the  nest  of  dry¬ 
ers  into  several  groups,  capable  of  variations  of  speed  has 
some  advantages  in  making  fine  papers,  because  it  really  permits 
the  paper  to  shorten  as  it  drys.  It  does  not  lend  itself  so  well 
to  rapid  production  of  large  quantities  of  paper  and  almost 
the  only  case  where  the  dryers  are  split  into  nests  in  America 
is  where  it  is  desired  to  insert  a  press  for  animal  sizing  between 
the  two  halves  of  the  dryers. 

Frequently  the  dryers  are  arranged  in  three  tiers  instead  of 
two.  This  permits  of  some  economy  in  space  and  also  conserves 
heat  to  a  certain  extent. 

Some  installations  of  dryers  have  been  made  where  the 
dryers  are  stacked  up,  one  above  the  other,  in  two  vertical 
stacks.  This  is  very  economical  of  space,  but  must  be  a  very 
troublesome  arrangement.  The  dryers  have  to  be  reached  with 
iron  ladders  and  the  handling  of  broke  and  the  making  of  ad¬ 
justments  and  repairs  on  such  a  set  of  dryers  must  be  a  matter 
of  great  difficulty.  However,  for  drying  thick,  heavy  papers  such 
dryers  would  have  the  advantage  of  conserving  the  heat  units 
to  a  maximum  extent  as  the  heated  air  from  the  lower  dryers 
would  aid  in  the  drying  of  the  paper  on  the  upper  units. 

Another  similar  device  is  the  placing  of  the  dryers  in  a 
gallery  supported  over  the  wire,  couch  and  presses.  This  is 
solely  to  economize  space.  The  best  proof  that  there  is  little 
real  necessity  for  all  such  innovations,  and  that  the  conventional 


328  MODERN  PULP  AND  PAPER  MAKING 

arrangement  of  paper  machine  parts  is  best  in  the  long  run, 
is  the  fact  that  such  peculiar  installations  are  so  rare.  As  a 
rule  paper  mills  are  built,  in  America  at  least,  in  localities 
where  space  is  not  at  a  great  premium  and  where  the  usual  form 
of  paper  machine  is  by  long  odds  the  best. 

Heating  of  Dryers:  The  dryers  must  be  piped  in  such  a  man¬ 
ner  that  the  sheet  of  moist  paper  will  not  be  scalded  when  it  starts 
through  the  dryer.  This  is  accomplished  by  having  the  first  dry¬ 
ers  next  to  the  presses  considerably  cooler  than  those  further 
along.  In  this  way  the  temperature  and  the  drying  effect  is  raised 
gradually.  There  must  be  drying  capacity  enough  to  dry  the 
paper  at  the  required  rate  of  speed  without  the  exertion  of  undue 
force.  If  the  sheet  is  seered  or  scalded  at  the  beginning  of  the 
drying  operation  it  traps  moisture  in  the  top  of  the  sheet,  thus 
requiring  a  great  deal  more  steam  to  dry  it,  besides  destroying 
some  of  the  qualities  desired  in  the  paper. 

There  are  different  opinions  as  to  the  best  methods  for  re¬ 
moving  the  condensation  water  from  the  dryers.  It  is  very 
necessary  that  this  water  should  be  removed  rapidly  and  regu¬ 
larly.  Some  operators  favor  siphons  and  some  systems  of 
dippers.  It  is  objected  to  the  syphons  that  they  have  a  tend¬ 
ency  to  trap  air  in  the  dryers ;  the  syphon  pipe  is  supposed  'to  be 
sealed  in  the  water  lying  in  the  bottom  of  the  dryer.  A  ma¬ 
chine  standing  idle  over  Sunday  becomes  cold.  Upon  starting  on 
Monday  morning  when  the  steam  is  admitted,  the  cold  air  is 
forced  to  the  front,  sometimes  remaining  in  this  condition  for 
hours.  This  makes  the  front  side  of  the  dryer  cooler  than  the 
back,  causing  an  irregularity  in  the  drying  of  the  paper.  Many 
schemes  for  extracting  this  air  have  been  tried.  Some  operators 
put  a  small  valve  on  the  front  end  of  each  dryer  to  let  out  the 
air,  just  as  air  is  let  out  of  a  steam  radiator  in  a  house  heat¬ 
ing  system.  It  is  also  contended  that  syphons  are  wasteful  of 
steam. 

When  systems  of  dippers  are  used,  the  dippers  are  neces¬ 
sarily  bolted  to  the  interior  of  the  dryer  cylinder  and  revolve 
with  it.  Water  is  dipped  up  at  every  revolution  of  the  dryer 
and  spills  into  the  pipes  and  passes  out.  It  is  held  by  some  that 
this  method  causes  a  waste  of  steam,  since,  as  the  dryers 
revolve,  the  dippers  are  at  the  top  one-half  of  the  time,  and  then 
being  exposed  to  the  direct  pressure  of  the  steam  inside  the 
dryers,  it  is  supposed  that  the  steam  blows  straight  through  and 
out  of  the  drip  pipes. 

Machine  builders  place  a  trap  on  the  inside  of  the  dryer 
intended  so  that  the  drip  pipe  is  never  empty.  Some  of  these 
traps  are  more  efficient  than  others  while  the  dripper  is  exposed  to 
the  pressure  of  the  steam. 

Whether  syphons  or  dippers  are  used  they  should  be  kept 
in  the  best  of  condition.  The  pipes  entering  the  neck  of  the 
dryer  should  never  be  permitted  to  rub  against  the  dryer,  form- 


THE  MACHINE  ROOM 


329 


ing  holes,  as  in  this  way  the  efficiency  of  both  parts  of  the  ap¬ 
paratus  is  impaired.  Under  such  conditions  the  steam  is  blown  in 
and  out  of  the  dryer  before  it  has  done  its  work.  The  presence 
of  holes  in  these  pipes  also  prevents  the  removal  of  water. 
Dryers  are  often  found  half  full  of  water  when  the  pipes  are 
in  this  condition. 

Dryers  cannot  be  maintained  in  proper  efficiency  without  con¬ 
stant  and  intelligent  supervision.  If  the  dryers  drain  into  a 


Fig.  132. — Witham  system  of  automatic  temperature  control  for  dryers. 

hot  well  and  this  hot  well  is  not  drained  over  Sunday  and 
remains  sealing  the  pipe  from  the  dryers,  the  dryers  will  suck 
the  water  up  as  they  cool  and  become  full  of  cold  water  by 
Monday  morning.  This  is  typical  of  the  large  number  of  small 
points  that  have  to  be  constantly  remembered  and  cared  for  in 
connection  with  dryers. 

The  proper  piping  of  the  steam  to  the  dryers  cannot  receive 
too  careful  attention.  Piping  dryers  on  a  paper  machine  is  a 
piece  of  work  that  varies  markedly  from  ordinary  piping  for 
steam  radiation,  coils  and  other  apparatus,  to  such  an  extent  that 
an  ordinary  piper  or  piping  contractor  should  never  be  per¬ 
mitted  to  introduce  his  own  theories  or  ideas,  but  should  be 
guided  entirely  by  the  judgment  of  some  persons  thoroughly  ex- 


MODERN  PULP  AND  PAPER  MAKING 


330 

perienced  in  the  art  of  drying  paper.  Nearly  all  mills  have 
different  conditions  which  must  be  considered. 

The  writer  has  seen  dryers  piped  up  at  the  wet  end  from 
the  exhaust  of  the  steam  engine  attached  to  the  machine,  and 
the  dry  end  piped  up  with'  a  i^'  or  2-inch  steam  line  direct 
from  the  boilers,  carrying  from  90  to  100  pounds  pressure  and 
only  equipped  with  an  ordinary  valve,  the  degree  to  which  this 
valve  should  be  opened  being  left  to  the  judgment  of  the  or¬ 
dinary  machine  help.  It  is  obvious  that  such  an  arrangement 
as  this  can  cause  all  kinds  of  trouble.  In  the  first  place,  there 
is  constant  danger  of  blowing  the  dryers  to  pieces.  In  any 
case,  the  live  steam  lines  will  counteract  the  engine  exhaust, 
causing  back-pressure  which  slows  down  the  engine  and  con¬ 
sequently  the  machine. 

The  paper  is  taken  from  the  last  press  (either  second  or 
third),  and  carried  around  the  dryers,  under  the  bottom  and 
over  the  top,  and  being  threaded  in  this  zig-zag  manner  the 
web  of  paper  is  held  tight  against  the  cylinders.  When  the 
web  has  passed  the  last  dryer  there  is  but  from  5  to  10  per 
cent  of  moisture  in  it. 

Automatic  tighteners  should  be  provided  so  that  the  sheet 
will  at  all  times  be  hugged  tightly  against  the  hot  surface  of 
the  dryers  to  prevent  it  from  cockling,  uneven  shrinkage,  and 
to  insure  even  drying. 

Dryer  Felts. 

Dryer  felts  are  among  the  most  difficult  of  paper  machine 
accessories  to  manipulate.  They  are  made  of  very  hard  and 
firm  material — do  not  stretch  like  woolen  felts,  except  by  wetting 
and  drying.  If  by  any  means  they  become  wrinkled,  such 
wrinkles  are  usually  there  to  stay. 

All  rolls  and  dryers  over  which  these  felts  must  run  should 
be  absolutely  level  and  in  line.  Rolls,  whether  of  wood  or 
iron,  should  be  absolutely  true. 

Dryer  felts  should  be  equipped  with  an  automatic  tightener 
roll.  They  are  subject  to  such  a  variety  of  conditions  on  ac¬ 
count  of  the  heat  of  the  dryers,  the  moisture  of  the  paper,  the 
speed  of  the  machine,  etc.,  that  it  is  very  necessary  that  this 
take-up  roll  should  be  very  sensitive,  to  respond  to  all  the 
variations. 

Carrying  rolls  not  in  proper  alignment  with  the  dryer  felt 
are  sure  to  cause  the  felt  to  travel  from  one  side  of  the  machine 
to  the  other,  and  in  many  cases  to  wrinkle.  Corner  rolls,  espe¬ 
cially,  must  be  in  perfect  adjustment. 

Dryer  felts  should  be  equipped  with  automatic  guides  which 
will  respond  readily  to  the  slightest  variations  of  the  felts. 

Old-time  paper  makers  often  believe  in  pulling  wrinkles  out  of 
dryer  felts  which  is  bad  practice,  and  after  thesq  felts  become 


THE  MACHINE  ROOM 


331 


wrinkled  straight  around  their  entire  length,  they  believe  in 
steaming  or  wetting  the  wrinkle.  They  have  many  other  notions 
equally  as  bad,  but  the  only  sure  and  true  way  to  take  care 
of  these  felts  is  to  have  the  rolls  properly  lined-up  and  level  and 
have  them  turned  round  and  true. 

The  best  results  are  obtained  with  reference  to  the  widths 
of  dryer  felts,  by  having  them  overhang  the  dryers  on  either 
edge  from  2  inches  to  4  inches,  as  they  then  run  much  more 
steadily  on  the  machine.  These  edges  not  coming  in  contact 
with  the  dryers  on  account  of  their  overhanging,  have  a  tendency 
to  shrink  a  little  more  than  the  remaining  part  of  the  felt,  and 
thus  act  as  a  resistance  against  any  influence  to  move  them  from 
one  side  of  the  dryers  to  the  other. 

Replacing  Dryer  Eelts:  If  the  machine-tender  will  give  a  rea¬ 
sonable  amount  of  his  attention  to  the  condition  of  the  felt  he 
will  be  forewarned  as  to  its  giving  out,  so  that  a  new  felt  may  be 
gotten  in  readiness  to  put  on,  as  the  new  felt  is  led  across  the 
dryers  by  tying  or  stitching  one  end  of  it  to  an  end  of  the  old. 
If  the  dryer  felt  should  break  apart  without  being  observed  by  the 
machine-tender,  it  would  probably  catch  and  wind  around  one 
of  the  dryers,  or  possibly  run  off  from  the  machine  entirely. 

If  the  former  should  happen,  it  would  be  a  hard  matter  to 
remove  the  felt  from  the  dryer,  as  it  could  not  be  unwound, 
but  would  have  to  be  cut  off  in  pieces.  Furthermore,  the  losing 
of  a  felt  from  the  dryers  often  results  in  breaking  or  disabling 
the  machine. 

In  putting  a  new  felt  on  the  machine,  the  dryers  should 
be  stopped  and  the  old  felt  cut  straight  across  that  portion  near¬ 
est  the  second  press ;  the  new  felt  can  then  he  laid  on  the 
floor  between  the  second  press  and  the  dryers  if  the  bottom  felt 
is  to  be  replaced,  or  laid  across  the  doctor  of  the  second  press 
of  the  top  one.  The  new  felt  should  be  seamed  to  an  end  of 
the  old,  where  it  has  been  cut,  to  that  portion  which  carries  around 
the  dryer.  A  man  should  be  stationed  on  either  side  of  the 
felt  to  help  feed  it  along  and  keep  it  in  alignment  with  the 
machine,  being  careful  that  it  does  not  get  tangled  up;  while 
two  or  three  men  should  take  the  remaining  end  of  the  old  felt 
and  pull  it  along  as  fast  as  it  comes  off.  The  old  felt  can  some¬ 
times  be  so  led  off  from  the  machine  as  to  be  able  to  put  it  on  one 
of  the  reels  and  wind  it  up  in  a  roll,  a  strong  friction  being 
applied  so  that  the  felt  can  be  pulled  off  without  the  aid  of  men ; 
but  unless  conditions  are  very  favorable,  it  is  best  to  run  it  off 
onto  the  floor  into  snug  folds. 

When  starting  to  lead  a  new  felt  over  the  dryers  it  is  also 
necessary  to  have  a  reliable  man  to  operate  the  dryer  friction 
so  that  the  felt  may  be  led  very  slowly  and  carefully  over  the 
dryers.  When  the  felt  has  nearly  reached  its  length,  care 
must  be  taken  not  to  run  it  too  far,  but  to  stop  the  dryers 
at  the  proper  time  so  that  both  ends  of  the  new  felt  are  in 


MODERN  PULP  AND  PAPER  MAKING 


332 

proper  place  to  seam.  It  must  be  borne  in  mind  that  if  the 
felt  is  run  3  or  4  feet  farther  than  it  should  be  it  is  very 
awkward,  and  perhaps  impossible  to  join  the  two  ends  of  the 
felt  without  going  over  all  the  dryers  and  rolls  and  pulling 
back  the  felt  by  hand,  to  a  convenient  place  where  the  seam 
can  be  made. 

Felt  Seams:  There  are  several  different  methods  of  joining 
the  end  of  these  felts  when  putting  them  on  the  machine.  The 
lap,  or  what  is  sometimes  called  the  boot-leg,  seam  gives  good 
results.  This  is  made  by  bringing  the  two  ends  together  and 
stitching  a  seam  evenly  across,  through  both  plys,  from  2  to  3 
inches  back  from  the  ends.  Slacking  the  stretch  roll  back  as 
much  as  possible  and  removing  a  roll  or  two  usually  gives  slack 
enough  to  do  the  seaming.  Such  a  seam  usually  comes  next  to  the 
paper;  this  answers  very  well  for  news,  hanging,  bag  or  Manila 
papers. 

The  seam  above  mentioned  is  likely  to  give  better  results 
if  one  ply  is  cut  slightly  shorter  than  the  other — perhaps  1^4 
inches — so  that  the  two  ends  will  not  come  squarely  together, 
thus  reducing  the  abruptness  of  the  two  thicknesses.  In  cutting 
the  felt,  both  ends  should  be  drawn  up  as  tightly  as  possible, 
after  the  stretch  roll  has  been  slacked  back,  and  a  roll  re¬ 
moved,  and  tacked  to  a  straight  edge  usually  kept  for  this 
purpose,  care  being  taken  that  both  edges  of  the  felt  are  in 
perfect  line  with  each  other.  The  ends  may  then  be  cut  off, 
making  necessary  allowance  for  the  lap  in  the  seam,  care  being 
taken  that  each  end  is  cut  to  follow  a  thread.  The  seam  can 
then  be  made. 

Fine  book  papers  being  more  sensitive  to  clumsy  or  thick 
seams,  it  has  been  found  best  to  use  in  this  connection  the 
seam  made  by  butting  the  two  ends  of  the  felt  together  and 
putting  in  what  is  called  a  herring-bone  stitch.  This  method 
does  away  with  the  objectionable  thick  seam  above  described. 

In  adjusting  the  stretch  roll  care  must  be  taken  not  to  run 
one  end  of  the  roll  very  far  ahead  of  the  other,  as  it  must 
be  remembered  that  a  dryer  felt  is  of  a  very  unyielding  nature 
— not  at  all  like  a  woolen  felt,  which  stretches  out  and  has  a 
flexibility  which  yields  to  the  tension  of  the  rolls.  It  must  not 
be  expected  that  the  seam  of  the  dryer  felt  will  run  absolutely 
at  right  angles  with  the  machine.  If  one  end  of  the  seam  is  a 
little  ahead  of  the  other,  but  the  felt  runs  smoothly  over  the 
dryers  and  rolls,  it  should  be  allowed  to  remain  in  that  condition, 
there  being  no  cause  for  worry  on  that  account.  It  is  time 
enough  to  change  the  stretch  roll  when  the  felt  shows  signs  of 
wrinkling  over  the  corner  and  loop  rolls.  These  present  the 
sharpest  angles  for  the  felt  to  pass  over,  and  are  the  places 
which  should  receive  attention  when  a  felt  shows  signs  of 
troubling. 

Dryer  felts  should  be  strained  up  tight  enough  to  prevent 


THE  MACHINE  ROOM 


333 


the  paper  from  cockling,  but  never  tight  enough  to  leave  the 
imprint  of  the  Aveaving  of  the  felt  in  the  paper,  or  to  cause 
the  felt  to  wrinkle.  A  little  careful  observation  will  teach 
the  machine-tender  about  where  the  tension  of  the  felt  should 
be.  The  use  of  an  automatic  tightener  is  supposed  to  regulate 
the  tightness  of  the  felt  -under  various  conditions. 

The  weight  of  the  canvas  from  which  these  dryer  felts 
are  made  should  depend  very  largely  upon  the  conditions  to 
be  met  with  on  the  various  machines. 

Guide  Rolls:  The  guiding  of  the  felt  and  the  position  of  the 
guide  roll  should  be  calculated  in  a  way  that  they  may  have  the 
greatest  control  over  the  felt.  If  two  carrying  rolls  be  placed 
12  ft.  apart,  it  is  always  best  to  place  the  guide  roll  at  least 
8  ft.  toward  the  roll,  following  the  direction  in  which  the  felt 
is  traveling.  It  sometimes  happens  that  the  guide  rolls  are 
placed  3  or  4  ft.  nearer  the  roll  in  the  reverse  direction,  giving 
a  very  short  draw  from  the  roll  as  the  felt  approaches  the 
guide  roll.  The  short  distance  between  the  roll  and  the  guide 
roll,  coupled  with  the  unyielding  nature  of  the  felt,  makes  it 
impossible  for  the  felt  to  respond  quickly  to  the  guide  roll.  Im¬ 
mediately  after  passing  the  guide  roll,  the  felt  has  a  long  stretch 
to  travel  before  passing  another  roll,  the  result  being  that  it 
is  very  likely  to  drift  back  again,  thereby  losing  a  part  of  the 
distance  which  it  has  been  brought  by  the  guide  roll.  The 
reverse  condition  would  operate  more  satisfactorily ;  that  is — 
if  the  roll  be  placed  as  above  described,  so  that  the  long  dis¬ 
tance  betAveen  the  back  roll  and  the  guide  roll  would  yield  more 
readily  to  the  influence  of  the  guide,  and  the  short  distance  be¬ 
tween  the  guide  and  the  roll  ahead  of  it  would  have  a  tendency 
to  hold  the  full  amount  that  has  been  gained  by  the  guide  roll. 
It  may  be  said  that  this  plan  is  applicable  to  any  felt. 

Briefly — the  guide  roll  should  be  placed  so  that  the  felt 
may  be  easily  turned  to  one  side  or  the  other,  and  the  roll 
following  should  be  near  enough  to  hold  all  that  the  guide  roll 
has  accomplished. 

Automatic  guides  should  be  of  such  a  type,  and  so  delicately 
adjusted,  that  the  least  pressure  on  the  edge  of  the  dryer  felt 
will  be  sufficient  to  turn  the  guide  roll  without  turning  the  edge 
of  the  felt.  The  guide  roll  should  never  be  placed  between 
two  rolls  very  near  together,  or  so  high  that  the  arc  of  contact 
of  the  felt  on  the  roll  shall  prevent  the  guide  roll  from  swinging 
easily,  or  shall  bind  it  in  any  way.  The  felt  should  run  over 
the  top  of  the  guide  roll,  inclining  downward  slightly  on  either 
side. 

Water  should  never  be  allowed  to  drip  on  the  top  dryer  felt. 
The  steam  and  condensation  should  be  extracted  from  the 
hood  over  the  machine,  if  there  is  one,  in  such  a  manner  as 
to  prevent  any  dripping.  This  subject  of  ventilation  is  discussed 
in  detail  in  Chapter  XV.  The  chemicals,  especially  alum,  con- 


MODERN  PULP  AND  PAPER  MAKING 


334 

tallied  in  paper  stock,  rot  a  felt  out  very  quickly  if  the  drip  be 
ever  so  slight;  they  also  cause  wet  streaks  in  the  paper,  which 
are  very  objectionable,  even  if  they  are  dried  out  before  finally 
reaching  the  reel,  as  other  portions  of  the  paper  must  necessarily 
be  over-dried  in  order  to  eliminate  the  moisture  in  these  par¬ 
ticular  streaks. 

Care  must  be  exercised  in  rinsing  up  around  the  press  near¬ 
est  the  dryers,  that  no  water  be  spattered  on  the  dryer  felt,  as 
this  also  has  a  tendency  to  rot  the  felt  and  thus  shorten  its 
service. 

The  careless  use  of  spears  for  removing  paper  that  has  be¬ 
come  wound  around  the  dryers  should  not  be  permitted.  There 
is  a  temptation  for  machine  help  to  assume  too  great  risk,  the 
spear  being  frequently  caught  between  the  dryer  and  the  felt,  and 
taken  around  the  dryer,  which  results  in  tearing  holes  and  some¬ 
times  destroying  the  felt.  If  the  dryers  become  clogged  with 
paper,  they  should  he  stopped  long  enough  to  cut  it  straight 
across,  and  started  very  slowly  so  that  the  paper  may  be  rolled 
up  and  removed  without  danger  or  injury. 

The  dryer  felt  running  next  to  the  press  nearest  the  dryers, 
should  always  be  protected  by  a  good  strong  guard.  The  space 
between  the  dryer  felt  and  this  press  is  so  limited  that  there  is 
great  danger  of  machine  operators  getting  caught  between  the 
felt  and  the  first  dryer. 

Pony  Dryers. 

Pony  Dryers  are  drying  cylinders,  similar  to  those  that  dry 
the  paper,  but  smaller  (usually  24  to  30  inches  in  diameter), 
running  in  roller  bearings  and  not  connected  with  the  ordinary 
dryer  drive  being  revolved  by  the  friction  of  the  felt.  They  are 
so  placed  as  to  dry  the  felt  as  it  passes  back  from  the  last 
dryer  to  the  first  so  that  it  will  be  in  condition  to  give  maximum 
efficiency  at  the  wet  end  of  the  dryer.  These  pony  dryers  are 
especially  useful  when  pushing  a  machine  to  the  limit  of  its 
capacity.  It  will  be  appreciated  that  if  moisture  were  allowed 
to  remain  in  the  felt  each  time  that  it  made  a  revolution  this 
condition  would  gradually  build  up  a  moisture  content  in  the 
felt  that  would  result  in  it  finally  running  very  wet,  even  at  the 
dry  end. 

Dryer  Felt  Rolls. 

These  rolls  are  made  of  iron  or  steel  pipe  from  6  to  12 
inches  in  diameter,  depending  on  the  width  of  the  machine. 
They  are  not  turned  down  as  this  would  reduce  the  thickness 
of  the  metal  too  much  in  certain  portions  of  the  pipe  and 
slight  irregularities  in  surface  are  unimportant  since,  owing  to 
there  being  a  number  of  these  rolls,  the  irregularities  will  correct 
each  other.  These  rolls  are  usually  heavily  galvanized. 


THE  MACHINE  ROOM 


335 


Dryer  Gears. 

Dryer  gears  should  be  cut  so  as  to  be  smooth  running  and 
avoid  back-lash.  A  jerky  condition  on  any  of  the  dryers  would 
put  undue  strain  on  the  paper  in  places  which  might  break 
it  and  in  any  case  would  be  detrimental  to  the  quality  by 
straining  the  fibres  apart. 

They  should  be  split  gears  to  facilitate  the  changing  of 
broken  gears. 

Machines  have  25  or  more  four-foot  dryers ;  it  is  customary 
to  drive  them  with  two  pinions.  These  pinions  have  to  start 
the  dryers  from  a  standstill  and  when  the  clutch  is  thrown 
in  there  is  a  terrific  lifting  tendency  on  the  dryers  immediately 
surrounding  these  pinions.  This  should  be  guarded  against  by 
having  very  strong  holding-down  caps  over  the  journals  on  the 
back  side.  If  the  dryers  lift  they  may  break  not  only  their 
own  gears  but  many  of  those  around  them.  Machines  are 
frequently  erected  without  these  holding-down  caps  but  we 
would  advise  that  they  be  supplied  and  demanded  in  specifi¬ 
cations  for  new  machines. 

Calenders. 

Calender  rolls  are  cast  and  chilled  and  must  be  of  fine 
grain  and  perfectly  free  from  blemishes  of  any  kind.  They 
have  to  be  most  carefully  ground  and  polished.  They  are 
mounted,  in  housings,  there  being  generally  from  seven  to  eleven 
in  a  stack,  the  whole  stack  being  driven  by  the  friction  of 
the  bottom  roll.  The  size  of  the  calender  rolls  depends  on  the 
width  of  the  machine.  The  bottom  roll  is  crowned  and  is 
usually  from  24  to  25  inches  in  diameter  on  a  156-inch  machine. 
On  small  machines  the  bottom  roll  may  be  only  18  inches  in 
diameter.  The  roll  next  to  the  bottom  is  smaller  than  the 
bottom  roll,  but  larger  than  any  of  the  succeeding  rolls.  All 
of  the  remaining  rolls  are  of  uniform  size  except  the  top  roll, 
which  is  somewhat  smaller  than  the  second  roll  but  larger  than 
any  of  the  intermediate  rolls. 

The  paper  enters  at  the  top  of  the  calender  stack  being  car¬ 
ried  across  from  the  dryers  and  under  a  spring  roll  which  ab¬ 
sorbs  any  tension  due  to  uneven  pull  between  the  dryers  and 
the  calender  stack. 

The  number  of  rolls  in  the  calender  stack  which  the  paper 
is  made  to  pass  between  is  variable  and  depends  on  the  finish 
desired  to  attain.  Sometimes  more  than  one  calender  stack  has 
to  be  used  to  get  the  desired  result.  On  some  water-finished 
paper  three  stacks  are  used,  one  small  and  two_  large.  The 
small  stack  is  placed  next  to  the  dryers  and  is  called  the 
breaker  stack. 

The  rolls  must  be  kept  in  perfect  alignment  and,  in  order 
to  preserve  this  alignment,  an  excellent  foundation  (concrete 


Courtesy:  Lobdell  Car  Wheel  Co.,  WUmingtcn,  Del. 

Fig-  133- — Typical  calender  stack. 

of  the  sheet,  all  the  rolls  as  well  as  the  bottom  one  must  be 
slightly  crowned  according  to  the  weight  carried. 

Calender  Doctors:  Calender  stacks  should  be  equipped  with 
doctors,  one  doctor  to  each  roll.  These  doctors  are  thin  steel 
blades  which  are  pressed  against  the  rolls  by  springs.  They  are 
beveled  so  as  not  to  scratch  or  score  the  roll  or  to  cause  anv 
perceptible  amount  of  friction.  The  function  of  the  doctors  is 
to  keep  the  rolls  free  from  little  specks  and  scabs  of  paper, 
lint,  dirt,  etc.,  which  would  all  tend  to  produce  calender  spots 
on  the  paper.  Also  they  prevent  the  paper  from  running  around 
the  roll  when  it  is  put  through  the  stack. 


336  MODERN  PULP  AND  PAPER  MAKING 

to  rock  or  something  equally  massive),  is  required.  Brass  fric¬ 
tion  rings  are  provided  to  take  care  of  the  ordinary  amount  of 
endwise  crowding  normally  present,  but  if  this  crowding  becomes 
excessive  the  cause  should  be  investigated.  It  will  frequently 
be  found  that  the  cause  is  a  worn  journal  box,  or  if  the  stack  is 
equipped  with  compound  weighted  levers,  these  levers  may  be 
pressing  unequally  on  one  of  the  two  sides. 

In  making  water-finished  paper  very  great  pressure  is  ap¬ 
plied  by  means  of  weights  and  levers  and  in  order  that  the 
application  of  this  weight  may  not  cause  pinching  at  the  edges 


THE  MACHINE  ROOM 


337 

When  a  wet  end  goes  through  the  calenders  the  rolls  be¬ 
come  covered  with  scabs.  Sometimes  the  doctors  will  not  remove 
these.  To  get  the  calenders  clean  the  doctors  should  be  re¬ 
leased  and  the  accumulation  of  lint,  paper  and  dirt  thoroughly 
cleaned  out.  A  little  kerosene  is  now  sprinkled  on  the  calender 
rolls.  When  the  paper  starts  going  through  a  little  water  or 
kerosene  can  be  sprinkled  on  the  paper.  This  will  usually  loosen 
all  the  scabs,  but  if  not,  the  back  tender  or  third  hand  can 
remove  the  obstinate  ones  with  a  calender  scraper.  The  paper 
going  through  the  calenders  while  this  is  being  done  should  not 
be  allowed  to  go  on  the  reels  but  should  go  into  the  broke. 

All  calender  stacks  should  be  provided  either  with  a  hydraulic 
lifting  equipment,  or  a  threaded  lift  operated  by  a  hand-wheel, 
with  which  to  lift  any  number  of  rolls  in  order  to  remove  wads 
of  paper  that  may  become  caugbt  between  tbe  rolls. 

Air  is  blown  against  the  calender  rolls  to  keep  them  cool 
and  to  insure  even  expansion  from  what  heat  is  inevitable. 
It  will  be  realized  that  in  such  large,  heavy  masses  of  metal 
as  calender  rolls  the  expansion  and  contraction  would  be  more 
or  less  uneven.  This  would  tend  to  press  the  paper  harder 
at  some  places  than  at  others  making  it  thinner  and  weaker 
there.  When  a  roll  shows  soft  spots  a  strong  air  blast  should 
be  directed  against  the  calender  rolls  just  at  that  point,  as  this 
part  of  the  calender  roll  must  have  become  overheated.  Over¬ 
heating  frequently  occurs  at  the  ends  of  the  rolls.  Sometimes  the 
paper  comes  from  the  dryers  more  perfectly  dried  at  one  place 
than  another,  thus  carrying  more  heat,  and  this  tends  to  heat 
the  calender  rolls  unevenly. 

Reels. 

There  are  two  different  types  of  reels — stack  reels  and  re¬ 
volving  reels.  Stack  reels  are  put  one  on  top  of  the  other  in 
a  vertical  frame — usually  two  reels  to  a  frame,  sometimes  three. 
The  frames  are  so  constructed  as  to  permit  the  reels  being  taken 
out,  after  they  are  filled  for  the  purpose  of  rewinding.  After 
the  reels  are  removed  from  the  stack  they  are  placed  on  a 
separate  set  of  stands  for  rewinding  into  smaller  rolls  or  for 
cutting  off  into  sheets. 

It  is  extremely  dangerous,  especially  in  case  of  high-speed 
news  machines,  to  allow  one  reel  to  be  winding  up  and  another 
reel  unwinding  in  the  same  stack,  because  if  a  man’s  hand  or 
arm  gets  caught  between  tbe  two  reels  he  is  sure  to  be  drawn  in 
and  killed.  This  accident  is  unfortunately  not  uncommon  in 
paper  mills. 

Revolving  reels  consist  of  a  set  of  reels  arranged  in  the  form 
of  a  cylinder.  It  is  really  a  reel  of  reels.  The  housing  carry¬ 
ing  the  reels  revolves  so  that  by  the  time  one  reel  is  filled  an¬ 
other  is  in  position  to  take  its  place,  and  similarly  by  the  time 
one  reel  is  almost  unwound  another  full  reel  is  in  position  for 


Courtesy ;  The  Pusey  and  Jones  Co.,  VCilmington,  Del. 

Fig.  134.— Two-drum  vertical  reel. 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  135. — Four-drum  semi-automatic  revolving  reel,  of  type  used  with 
moderate  speed,  medium  width  machines. 

338 


THE  MACHINE  ROOM 


339 

unwinding.  These  reels  are  specially  adapted  where  the  paper 
is  taken  from  the  reel  to  be  cut  into  sheets. 

The  stack  reels  are  driven  with  a  clutch  and  a  friction 
belt  is  provided  so  the  speed  of  the  reel  can  be  controlled, 
both  in  winding  when  care  must  be  exercised  not  to  break  the 
paper,  and  in  unwinding  when  friction  must  frequently  be  ap- 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 


Fig-  136. — Another  type  of  semi-automatic  revolving  reel  having  six 
drums  and  being  intended  for  high  speed  newsprint  machines. 


plied  to  keep  the  reel  from  going  too  fast  and  allowing  the  paper 
to  become  slack. 

1  he  revolving  or  cylinder  reels  are  driven  by  a  gear  arranged 
so  that  the  gear  for  each  reel  meshes  into  the  driving  gear  when 
the  reel  reaches  a  certain  point  in  its  revolution.  These  reels  are 
also  provided  with  frictions  for  the  same  purposes  as  in  the  case 
of  the  stack  reels. 

Winders. 

The  winder  is  a  machine  for  taking  the  paper  from  the 
reels  and  winding  it  in  rolls  of  any  desired  size  and  at  the  same 
time  cutting  the  paper  into  any  desired  width,  which  it  does 
by  means  of  knives  that  press  on  the  paper  as  it  is  moving 
from  the  reel  to  the  winder.  The  usual  form  of  knife  is  a 
revolving  one.  These  knives  are  known  as  slitters.  Sometimes 
they  are  actuated  by  power  and  sometimes  by  the  friction  of  the 
paper.  There  are  a  great  many  makes  of  these  winders  in  use. 
This  equipment  will  be  described  in  detail  in  the  chapter  on  the 
finishing  room. 


340 


MODERN  PULP  AND  PAPER  MAKING 


The  Cylinder  Machine. 

The  cylinder  machine  consists  of  one  or  more  cylinders 
covered  with  wire,  like  the  wire  of  the  Fourdrinier  machine, 
immersed  in  a  vat  of  stock  in  which  they  rotate.  For  the  sake 

of  simplicity,  we 


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will  first  describe  a 
single  cylinder  ma¬ 
chine.  As  the  cylin¬ 
der  revolves  in  the 
vat,  naturally  the 
stock  tends  to  flow 
through  the  wire 
and  the  fibres  being 
unable  to  pass  are 
caught  in  a  web  on 
the  wire.  The  water 
that  passes  through 
the  wire  is  drained 
off  from  the  end  of 
the  cylinder.  The 
difference  in  level 
between  the  water 
in  the  cylinder  and 
the  stock  in  the  vat 
provides  a  suction 
that  keeps  forming 
a  film  on  the  wire 
as  the  cylinder 
moves  around.  Fac¬ 
ing  the  head  of  the 
cylinder  is  a  plate 
of  the  same  size  and 
shape  as  the  head, 
and  around  the 
combined  edge  of 
the  cylinder  head 
and  this  plate  is  a 
band  tight  enough 
to  preserve  the  suc¬ 
tion  from  the  cylin¬ 
der,  but  not  too 
tight  to  interfere 
with  the  revolution 
of  the  c  y  1  in  d  e  r. 
The  amount  of  the 
suction  and  conse¬ 
quently  the  thick- 


THE  MACHINE  ROOM 


341 


ness  of  the  layer  of  fibres  formed  on  the  cylinder  is  regulated  hy 
the  height  at  which  the  water  is  allowed  to  stand  in  the  cylinder. 
This  is  governed  hy  a  diaphragm  controlling  the  opening  by 
which  the  water  drains  away  from  the  cylinder. 

The  long  straight  fibres  are  naturally  drawn  against  the 
cylinder  wire  head  on,  like  logs  going  down  stream,  and  to  prevent 
this  action,  which  would  not  give  as  good  a  sheet  as  if  the  fibres 
felted  and  matted  more  on  the  screen,  various  devices  are  in¬ 
serted  in  the  vat  to  keep  the  stock  in  motion  so  that  the  fibres 
will  be  compelled  to  pass  the  surface  of  the  screen  with  their 
length  parallel  to  it  to  a  greater  or  less  extent,  and  consequently 
be  pulled  against  it  by  the  suction  sideways. 

At  the  top  of  the  cylinder  is  a  couch  roll  over  which  passes 
a  felt  moving  in  the  same  direction  as  the  surface  of  the  cylinder. 
This  felt  picks  up  the  film  of  fibres  and  carries  it  along  through 
one  or  two  pairs  of  squeeze  rolls  to  the  presses  and  dryers  which 
are  arranged  like  those  of  the  Fourdrinier  machine. 

For  making  heavy  boards,  which  consist  of  layers  of  several 
different  kinds  of  paper,  after  the  felt  has  passed  over  the 
first  cylinder  it  may  pass  over  a  second  cylinder,  revolving  in  a 
vat,  receiving  another  layer  of  paper,  and  in  the  same  manner 
a  third  and  fourth — as  many  as  eight  sometimes  being  used. 

Harper  Fourdrinier  Machine, 

The  Harper  Fourdrinier  machine  closely  resembles  an  or¬ 
dinary  Fourdrinier  machine  with  the  entire  portion  preceding 
the  presses  turned  around  end  for  end.  In  other  words  the  wire 
is  travelling  away  from  the  presses,  instead  of  towards  them. 
The  paper  formed  on  the  wire  is  carried  back  from  the  couch 
rolls  on  a  long  felt  (which  is  carried  on  rolls  high  over  the 
wire),  which  supports  the  paper  until  it  enters  the  presses  and 
sometimes  even  until  it  enters  the  dryers. 

The  chief  usefulness  of  this  machine  is  due  to  the  fact  that 
the  paper  is  constantly  supported  by  a  felt,  or  some  other  sur¬ 
face,  there  being  no  gaps  to  bridge,  as  between  the  couch  rolls 
and  presses  in  the  ordinary  Fourdrinier  machine.  This  renders 
the  Harper  machine  valuable  for  making  very  delicate  papers  > 
such  as  tissues,  cigarette  paper,  crepe  papers,  etc.  Since  this 
kind  of  paper  requires  very  little  pressing,  there  is  frequently 
only  one  set  of  press  rolls  on  such  a  machine.  The  excessively 
long  felt,  often  100  feet  in  length,  is  one  of  the  undesirable  fea¬ 
tures  of  this  machine.  In  the  first  place,  it  is  very  expensive  and, 
secondly,  it  is  very  hard  to  keep  free  from  injury.  This  fact, 
together  with  the  upkeep  of  the  Fourdrinier  wire,  makes  the 
Harper  a  very  expensive  machine  to  maintain.  Consequent!}'  its 
use  is  restricted  to  those  kinds  of  paper  that  cannot  well  be 
made  on  any  other  machine,  as  outlined  above. 


342  MODERN  PULP  AND  PAPER  MAIUNG 

Yankee  Machine. 

The  essential  difference  between  a  Yankee  machine  and  a 
Fourdrinier,  Cylinder  or  Harper  is  the  method  used  in  finishing 
or  surfacing  a  sheet  of  paper  and  the  drying. 

The  Yankee  machine  has  one  very  large  dryer,  sometimes 
considerably  more  than  lo  feet  in  diam.,  while  the  ordinary 
machine  dryers  range  from  3  feet  to  5  feet  in  diam.  The  large 
dryer  which  is  used  on  Yankee  machines  has  a  very  highly 
polished  surface,  and  against  this  surface  a  set  of  press  rolls 
runs,  the  top  press  roll  coming  in  contact  with  the  surface  of 
the  dryer. 

The  press  rolls  are  permanently  fixed  and  the  dryer  is  screwed 
back  against  the  surface  of  the  press  roll  by  means  of  screw 
gears  and  hand  wheels.  This  is  so  that  when  the  paper  passes 
between  the  rubber  covered  press  rolls  and  dryer  it  can  be 
pinched  very  hard. 

There  is  also  usually  a  dryer  felt  covering  the  big  Yankee 
dryer  the  same  as  it  covers  ordinary  dryers,  care  being  taken  to 
get  all  of  the  drying  surface  possible  within  the  radius  of  the 
dryer. 

The  making  up  part  of  the  machine  is  precisely  the  same  as 
any  other  machine,  namely  straight  Fourdrinier  part,  wet  part 
of  Cylinder  machine  or  wet  part  of  Harper  Fourdrinier  ma¬ 
chine. 

Sometimes  there  are  small  intermediate  dryers  and  the  big 
Yankee  dryer  is  placed  at  some  advantageous  point  in  the 
section  of  dryers.  The  object  of  all  of  this  is  to  give  the  sheet 
of  paper  a  glossy  finish  on  one  side  only. 

The  speed  and  production  of  the  machine  is  limited  to  the 
capacity  of  the  big  dryer.  For  instance,  if  the  machine  was 
running  a  little  faster  then  the  big  dryer  would  dry  the  paper 
alone,  smaller  dryers  would  be  added  either  before  or  after  the 
sheet  passes  the  big  dryer,  usually  before. 

This  leaves  the  right  amount  of  moisture  in  the  paper  to  iron 
nicely  as  it  goes  over  the  dryer.  If  the  sheet  of  paper  is  too  wet 
it  does  not  give  the  desired  surface  or  dryness  and  if  it  is  too  dry 
it  takes  away  the  excellent  polish  obtained.  The  idea  is  very 
similar  to  laundry  work :  ironing  a  shirt  bosom,  for  instance.  It 
bas  always  to  be  sprinkled  to  a  certain  degree  of  moisture  be¬ 
fore  flat  irons  are  applied.  This  is  the  principle  of  the  Yankee 
machine. 

The  Yankee  machine  is  necessarily  slow  running  and  yields 
a  low  production  and,  as  before  stated,  it  is  limited  on  account 
of  operating  the  large  dryer. 

There  can  be  the  same  number  of  presses  and  the  same 
apparatus  to  form  the  sheet  and  get  it  ready  for  this  dryer,  as 
on  any  other  machine.  There  are  seldom  any  calenders  on  a 
Yankee  machine,  because  when  a  sheet  of  paper  goes  over  the  big 
dryer  it  is  supposed  to  be  finished, 


THE  MACHINE  ROOM  343 

This  machine  gives  an  excellent  shiny  surface  to  the  paper 
which  cannot  be  obtained  by  ordinary  calendering  but  it  only 
gives  the  surface  to  one  side  of  the  sheet,  the  sheet  of  paper 
being  hugged  so  tightly  against  this  dryer  by  the  dryer  felt  and 
moved  so  slowly,  that  by  the  time  it  goes  over  the  dryer  once  it 
is  ready  to  reel  up  nicely  finished. 

There  are  a  great  many  uses  for  this  paper,  such  as  for  the 
lining  of  duplex  paper  bags  with  the  shiny  side  inward.  It 
makes  a  very  satisfactory  appearance  for  a  bag  containing  cereals 
of  any  kind,  coffee,  teas,  confectionery,  etc.  Tissue  paper  is 
sometinies  finished  in  this  way,  especially  that  used  for  wrapping 
confectionery  goods.  It  is  also  used  for  paper  for  druggists’ 
purposes.  It  may  be  used  for  blank  leaves  in  technical  books, 
novels,  etc.,  where  a  nice  finish  is  desired.  Paper  napkins 
and  towels  and  all  sorts  of  paper  used  for  similar  purposes 
may  be  made  and  finished  on  a  Yankee  machine. 

The  Yankee  machine  is  adapted  for  thin  and  medium  weight 
papers  only,  ranging  from  tissues  to  not  thicker  than  35  or  40 
pound  paper. 

The  reason  for  this  is  also  on  account  of  the  limited  pro¬ 
duction  and  slow  running  of  such  a  machine,  because  all  of  the 
finish  that  it  can  possibly  get  is  while  the  big  dryer  is  making  one 
revolution. 

The  reason  for  putting  the  big  dryer  at  the  dry  end  of  the  or¬ 
dinary  dryers  is  so  that  the  ordinary  dryers  can  be  tempered  so 
that  the  paper  will  come  to  the  big  dryer  .with  just  the  right 
amount  of  moisture  to  give  it  the  ironing  effect.  The  whole 
machine  must  be  run  entirely  in  accord  with  the  big  dryer  and  its 
conditions,  drying  capacity,  etc. 

It  is  very  essential  that  the  surface  of  this  dryer  be  kept 
absolutely  clean.  In  many  instances  the  dryer  is  supplied  with 
some  sort  of  a  polishing  apparatus  like  a  revolving  buffer  or 
oscillating  doctor,  which  is  equipped  with  soft  material  that 
will  not  scratch  the  surface,  as  the  finish  of  the  paper  depends 
entirely  on  the  surface  of  this  dryer.  Any  scratches  or  creases 
caused  by  ordinary  doctors  dragging  on  the  surface  will  show 
up  in  the  paper  after  running  over  this  dryer. 

A  typical  Yankee  machine  has  no  additional  dryers,  but  these 
modifications  can  be  applied  in  case  of  necessity  to  come  nearer 
to  the  requirements  for  certain  grades  of  paper. 

Machine  Drive.^ 

The  general  practice  is  to  drive  all  the  moving  parts  of  the 
machine  from  a  line  shaft  situated  in  the  basement  under  the 
machine  room.  This  shaft  extends  the  length  of  the  machine 
and  is  usually  driven  by  a  belt  from  a  steam  engine  or  electric 


’The  installation  and  drive  of  paper  machines  -will  be  dealt  with  from  the  engi 
neenpg  standpoint  in  Chapter  XV. 


MODERN  PULP  AND  PAPER  MAKING 


344 

motor.  Turbine-driven  reduction  gears  have  been  tried  in  a 
few  instances.  Owing  to  the  length  of  this  shaft  it  is  not  ad¬ 
visable  to  have  the  engine  or  motor  direct  connected  to  it,  and 
should  this  arrangement  be  installed  for  any  reason  it  is  neces¬ 
sary  to  introduce  a  flexible  coupling  between  the  engine  and 
the  shaft. 

Steam  engines  are  generally  used  in  preference  to  motors  since 
the  exhaust  steam  is  afterwards  used  in  the  dryers.  Turbines 
might  seem  advantageous  for  this  purpose,  as  they  would  de¬ 
liver  exhaust  steam  free  from  oil,  whereas  oil  separators  have  to 
be  installed  between  the  engine  and  the  dryers.  However,  where 
turbines  have  been  used  other  facts  have  developed  that  militate 


Fig.  138. — Basement  of  machine  room  showing  machine  drive,  pumps  and 

save-alls. 


against  their  use.  The  turbine,  on  account  of  its  high  speed,  is 
little  adapted  to  the  paper  machine  service,  and  complicated  speed- 
reduction  gears  are  necessary  when  turbines  are  used. 

The  line  shaft  is  fitted  with  cone  pulleys  and,  from  these, 
belts  pass  up  through  scuppers  to  cone  pulleys,  mounted  on 
stands  specially  dtesigned  for  paper  machine  service,  which 
drive  the  lower  couch  roll,  lower  press  rolls,  dryers  and  bottom 
calender  roll.  These  stands  provide  for  belt  shifters  and  fric¬ 
tion  clutches,  so  that  the  belt  can  be  advanced  or  retarded  on 
the  cones  as  needed  and  that  particular  part  of  the  machine  can 
be  shut  down  independent  of  any  other  at  any  time. 

In  starting  the  machine  the  wire  is  first  started,  then  the 
presses  and  finally  the  dryers,  calenders  and  reels,  the  paper 
being  led  along  from  one  part  of  the  machine  to  the  next  by 
helpers.  It  is  then  necessary  to  adjust  the  tension  of  the  paper 
between  the  various  parts  of  the  machine.  If  the  paper  sags  too 


THE  MACHINE  ROOM  345 

much  between  the  couch  roll  and  the  first  press  it  is  obvious 
that  the  press  is  running  too  slow  in  relation  to  the  wire,  con¬ 
sequently  we  speed  the  press  up  a  little  and  slow  the  wire  down 
a  little  by  means  of  the  cone  pulleys.  If  the  paper  apparently 
pulls  in  two  between  the  couch  roll  and  the  first  press,  we  would 
assume  that  the  speed  of  the  press  was  too  high  in  relation  to 
that  of  the  wire  and  we  would  slow  down  the  press  a  little 
and  speed  up  the  wire.  In  this  way,  without  making  any  drastic 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Oet. 

Fig-  139- — Typical  cone  drive  with  box  bed  plate  suitable  for  large,  high 
speed  rnachines.  For  slower  and  smaller  machines  the  same  type  of 
drive  with  flanged  stands  is  frequently  used. 


alterations  in  speed  anywhere,  the  working  of  tne  entire  machine 
can  be  tuned  up,  so  there  is  no  undue  strain  on  the  paper 
anywhere. 

Starting  the  Paper  Machine. 

We  will  assume  that  the  engine  is  running  and  that  the  con¬ 
stant  and^  variable  speed  lines  are  both  up  to  speed  and  ready 
to  strike  in  the  machine. 

(i)  The  dryers  must  be  started  in  advance  of  the  other 
parts  of  the  machine  and  steam  must  be  admitted  to  the  dryers 
so  that  they  will  be  at  the  right  temperature  when  the  paper 
is  put  over.  The  dryer  felt  must  be  given  a  tension  to  see 
that  it  runs  steady  and  safely.  Steam  must  not  be  admitted  to 
the  dryers  before  they  are  started  since,  as  water  will  probably 
be  lying  in  the  bottom  of  the  cylinders,  they  would  be  heated 
unevenly  and  strained  on  account  of  the  unequal  expansion.  It 
is  also  desirable  to  open  the  drip  line  valve  to  its  full  extent 
when  the  steam  is  admitted  so  that  the  excess  water  will  be  blown 
out  quickly,  after  which  the  drip  valve  should  be  closed  to  a 
point  where  the  water  will  be  extracted  without  wasting  steam. 
A  three-  or  four-inch  drip  line  valve  should  be  open  not  more 
than  three  or  four  turns.  After  the  dryers  have  been  started 


346  MODERN  PULP  AND  PAPER  MAKING 

and  water  all  exhausted  the  inlet  valve  should  be  set  at  a  point 
adapted  to  the  sheet  of  paper  to  be  made. 

(2)  Each  woolen  felt,  on  the  first,  second  and  third  presses, 
should  be  got  into  proper  condition  by  starting  it  up  carefully. 
If  the  presses  have  been  left  up  prior  to  the  starting  of  the 
machine,  they  should  be  carefully  inspected  to  see  that  no  lumps, 
foreign  matter,  tools,  etc.,  are  lying  around,  and  then  the  presses 
should  be  let  down,  and  the  felt  started.^  I'he  shower  pipes 
should  then  be  opened,  giving  the  felt  a  sprinkling.  The  presses 
should  be  run  in  this  condition  until  the  felts  are  thoroughly 
saturated.  Then  the  water  should  be  shut  off  and  the  presses 
run  until  the  surplus  water  is  all  squeezed  out  and  the  felts  run¬ 
ning  smooth.  Then,  the  press  weights  are  put  on  the  levers. 
Be  sure  that  the  outlet  of  each  save-all  pan  under  each  set 
of  presses  is  clear,  to  prevent  water  from  running  down  onto  the 
felt.  Treat  each  and  every  felt  in  this  manner.  Then  shut 
them  all  down. 

While  this  is  being  done,  the  dryers  must  not  be  forgotten 

and  allowed  to  become  overheated. 

The  preceding  operations  are  usually  attended  to  by  the  back- 
tender  third  hand  and  fourth  hand.  Simultaneously  the  machine 
tender  is  getting  the  Fourdrinier  part  and  wire  in  readiness  to 
start. 

(3)  First,  the  entire  wire  is  given  a  thorough  inspection, 
making  sure  that  there  is  nothing  lying  around  on  the  wire  or 
near  it  that  will  injure  it.  The  wire,  deckle  straps,  apron  couch 
roll,  etc.,  are  thoroughly  washed  with  a  hose.  All  showers  are 
opened  wide.  The  wire  is  started  and  run  around  for  a  few 
minutes  to  make  sure  that  it  is  in  perfect  readiness  for  starting. 
All  levers  and  weights  on  the  couch  rolls  are  inspected,  to  see 
that  they  are  in  proper  place.  When  the  machine  tender  is  sat¬ 
isfied  that  his  wire  is  in  proper  condition  he  stops  it,  and  begins 
the  “furnishing  up”  of  the  vats,  screens,  pump  box,  head  box 
and  save-alls. 

(4)  First,  the  fresh  water  supply  is  opened.  All  hands 
stand  by  while  this  operation  is  going  on,  keeping  a  sharp  eye 
on  anything  that  might  need  attention.  The  back-tender  stands 
by  the  starting  lever  of  the  Fourdrinier  wire.  When  the  clear 
water  furnish  is  at  a  sufficient  height,  the  machine  tender  opens 
the  stuff  tap  in  the  stuff  box  at  the  back  side  of  the  machine. 
The  stuff  mixes  with  the  return  water  going  through  the  pump 
and  into  the  screens,  head  box  and  onto  the  apron.  The  ma¬ 
chine  tender  watches  the  furnish,  and  when  there  are  fibers 
enough  in  the  water  to  make  the  sheet  of  paper  he  gives  the 
signal  to  the  back-tender  to  throw  in  the  starting  lever  of  the 
wire.  The  back-tender  starts  the  wire  and  immediately  takes  up 
a  hose  and  starts  rinsing  the  jacket  of  the  couch  roll,  as  fre¬ 
quently  the  stuff  runs  up  around  against  the  guard-board, 
case  there  is  an  old  jacket,  which  has  become  threadbare,  difh- 


THE  MACHINE  ROOM 


347 

culty  in  keeping  the  stuff  from  running  up  around  the  roll  is 
encountered,  and  the  only  way  to  get  it  down  is  by  washing 
with  a  heavy  stream  of  water.  Care  must  be  taken  to  have  the 
guard-board  properly  adjusted  and  free  from  grit  and  particles 
of  stuff'  under  the  lip.  The  wiper  must  be  put  in  place,  and  the 
shower  on  the  jacket  run  as  wjde  open  as  may  be  without  run¬ 
ning  down  the  jacket.  During  this  operation,  extreme  care  and 
attention  must  be  given  to  the  save-all  under  the  couchers,  that 
the  stuff  may  not  pile  up  against  the  wire.  Also  to  see  that  the 
wash-roll  shower  and  doctor  on  the  roll  is  doing  its  work.  In 
fact,  the  wire  rolls  must  be  watched  all  the  way  along  during 
this  process  of  starting,  to  make  sure  that  no  lumps  collect  on 
any  of  the  carrying  rolls,  or  breast  roll. 

(5)  The  first  felt  is  then  started,  being  careful  that  no 
lumps  of  stock  have  fallen  onto  the  felt;  if  so,  they  must  be 
carefully  rinsed  off  before  the  felt  is  started.  The  third  hand 
operates  the  squirt  gun,  which  delivers  a  needle  stream  of  water 
on  the  wire,  which  cuts  a  narrow  tail-end.  This  tail-end  is 
lifted  from  the  bottom  couch  by  tbe  back-tender  and  onto  the 
first  felt.  This  tail-end  runs  up  onto  the  top  press  roll  of  the 
first  felt.  The  back-tender  steps  along  and  pulls  it  down  onto 
the  second  felt,  and  it  is  finally  put  up  into  the  third  press.  The 
back-tender  keeps  a  sharp  eye  on  this  operation,  and  at  the 
proper  time  signals  the  third  hand  to  slowly  push  in  the  squirt 
gun  and  gradually  widen  out  the  tail-end,  until  the  entire  sheet 
is  passing  through  to  the  third  press.  By  this  time  the  back- 
tender  has  taken  this  narrow  tail-end  (or  leader)  across  the 
dryers. 

(6)  The  proper  adjustment  of  the  weights  on  the  levers  of 
all  of  the  presses  must  be  carefully  taken  care  of.  At  the  same 
time  the  proper  temperature  of  the  dryers  cannot  be  forgotten, 
and  the  drying  apparatus  must  be  corrected  according  to  condi¬ 
tions. 

(7)  Machines  equipped  with  automatic  temperature  control 
may  be  set  at  the  desired  point  for  proper  drying. 

(8)  During  this  process  of  starting  up,  the  tension  between 
the  different  sections  must  be  carefully  observed,  as  at  this  par¬ 
ticular  stage  of  the  process  the  paper  is  extremely  delicate  and 
tender,  and  any  unnecessary  pulling  strain  between  the  sections 
will  either  cause  the  paper  to  break,  or  render  it  useless. 

(9)  The  paper  is  thus  taken  across  and  put  through  the 
calenders  at  a  point  sufficient  for  the  finish,  and  from  the  cal¬ 
enders  to  the  reels.  During  this  operation  the  machine  tender 
stays  up  at  the  wet  end  and  carefully  scrutinizes  everything  con¬ 
nected  with  the  Fourdrinier  part  making  such  corrections  and 
adjustments  as  will  ensure  the  safe  running  of  the  paper. 

(10)  If  a  dandy  is  used  the  dandy  must  be  thoroughly 
rinsed  and  cleaned,  and  let  down  onto  the  wire  before  tbe  paper 
has  been  carried  through  the  presses.  The  suction  boxes  back 


■348  MODERN  PULP  AND  PAPER  MAKING 

of  the  dandy  must  be  regulated  to  give  the  proper  moisture  to 
the  sheet  as  it  passes  under  it.  If  left  too  wet  the  dandy  is 
likely  to  leave  crush  marks  in  the  sheet.  If  left  too  dry,  it  is 
likely  to  lick  up  the  web  in  places ;  and  even  if  it  does  not  do  this, 
it  does  no  good  to  the  sheet  to  let  the  dandy  walk  on  it.  It  will 
be  apparent  that  there  can  be  no  impression  left  in  the  paper  by 
the  weight  of  the  dandy  if  the  sheet  is  too  dry. 


Weaving  Devices. 

There  is  a  strong  tendency  for  the  Fourdrinier  Machine,  no 
matter  how  efficiently  the  shake  may  be  arranged,  to  cause  the 
sheet  to  have  a  grainy  appearance.  In  other  words,  the  fibres  all 
point  in  one  direction  leading  to  excessive  strength  in  the  ma¬ 
chine  direction,  and  inferior  strength  in  the  cross  direction. 

To  overcome  this  feature  many  devices  have  been  made  to 
cross  these  fibres  in  order  that  the  strength  of  the  paper  may  be 
equalized.  It  is  very  essential  in  nearly  all  grades  of  papers, 
especially  bag  and  market  that  this  stage  of  equilibrium  exist 
or  otherwise  such  a  sheet  in  bag  use  splits  when  it  is  attempted 
to  carry  objects  of  any  appreciable  size  or  weight.  Such  a  sheet 
must  be  avoided  as  far  as  possible,  regardless  of  the  difficulty. 

A  recent  patent  covering  the  above  work  consists  of  a  re¬ 
volving  cylinder,  made  of  parallel  steel  rings,  revolving  at  the 
same  distance  in  the  shallow  depth  of  fibres  and  water,  prior  to 
reaching  the  suction  boxes.  As  soon  as  this  device  has  turned 
these  fibres  at  an  angle,  or  in  other  v/ords  crossed  them,  they 
come  in  contact  with  the  suction  box  which  in  turn  pulls  these 
fibres  down  and  holds  them  at  that  angle  before  they  have  an 
opportunity  to  straighten  themselves  out  again. 

This  particular  device  has  shown  in  many  instances  its  vast 
importance.  In  using  it,  however,  extreme  precaution  must  be 
taken  in  that  no  stock  or  particles  of  dirt  cling  to  the  parallel 
bars,  otherwise  more  particles  will  accumulate,  fall  off,  and  make 
spots  in  the  paper. 

Another  method  that  has  become  recognized  is  that  of  a  cross 
channel  device  placed  under  the  slices  prior  to  the  stock  going 
onto  the  wire.  This  apparatus  consists  of  an  aluminum  box 
the  width  of  the  machine,  about  one  foot  in  depth  and  six  inches 
in  height.  The  box  is  divided  into  two  compartments,  an  upper 
and  lower.  Each  compartment  is  further  subdivided  into  small 
channels  about  two  inches  in  width.  The  small  channels  of  the 
lower  compartments  are  all  directed  in  one  direction  at  an  angle  of 
approximately  45  degrees  with  the  slices.  The  channels  of  the 
upper  compartments  are  directed  directly  opposite  to  that  of  the 
lower  section,  thus  forming  two  currents  of  stock. 

With  the  use  of  this  device  the  amount  of  water  used  de¬ 
termines  the  nature  of  the  resulting  sheet.  If  a  large  amount 
of  water  is  being  used  at  the  slices  the  stock  and  water  is  forced 


•  THE  MACHINE  ROOM  349 

out  of  the  cross  fibre  device  with  great  force  and  the  stock 
tumbles  around  in  all  directions,  even  in  a  perpendicular  direction 
to  the  wire.  This  boiling  action  results  in  a  sheet  of  paper  that  is 
practically  equal  in  strength  in  all  directions  which  is  no  small 
feat  when  the  original  length  of  the  fibres  has  been  retained 
during  the  beating  and  refining  operations. 

If  on  the  other  hand  but  little  water  is  being  used  at  the 
slices,  the  two  compartments,  the  lower  and  upper,  practically 
form  the  two  webs  of  paper  containing  fibres  directly  opposite 
to  each  other.  This  sheet  has  all  the  appearance  of  a  duplex 
sheet. 

Cause  of  Breaks  on  the  Paper  Machine. 

Screens,  Spouts  and  Pipes:  All  screens,  spouts  and  pipes 
must  be  kept  thoroughly  cleaned  to  prevent  the  accumulation  of 
slime.  Slime  spots  are  caused  by  the  slime  which  has  collected 
on  spouts,  pipes  and  screen  vats  breaking  away  and  going 
through  onto  the  wire,  and  making  up  with  the  web.  If  a  slime 
spot  gets  by  the  couchers  and  presses  to  the  reels,  it  makes  dark 
spots,  sometimes  transparent,  and  more  often  leaves  a  hole  in 
the  paper  the  size  of  the  slime  spot. 

Head  Box:  Dead  corners  in  the  head  box  cause  lumps  to 
accumulate  and  break  away  occasionally.  The  head  box  should 
be  no  larger  than  necessary  and  all  square  corners  eliminated. 
Make  these  circular  when  possible  by  using  fillets. 

Apron:  Wrinkles  in  the  apron  causes  the  stuff  to  roll  and 
make  lumps.  Wrinkles  should  not  be  permitted.  Holes  in  the 
apron  cause  stuff  to  roll  intO'  small  hard  lumps.  Sometimes 
a  patch  can  be  temporarily  used.  A  poorly  folded  apron  causes 
stuff  to  work  back  under  apron  and  deckle  strap,  causing  bad 
edges  or  feather  edges.  The  apron  must  always  be  folded  with 
care  and  must  be  fastened  to  the  angles  in  a  way  that  will  make 
square  corners  between  the  angles  and  the  wire. 

Breast  Roll:  Stuff  carried  back  by  the  wire  to  the  breast 
roll  and  under  the  apron  will  roll  into  little  hard  lumps  and 
break  the  web.  This  can  be  eliminated  by  the  use  of  a  strong 
shower  of  water.  The  shower  pipe  must  be  so  located  as  to 
force  the  streams  of  water  up  and  between  the  apron  and  wire. 
This  will  prevent  lumps  from  accumulating  under  the  apron. 

Tube  Rolls:  These  must  be  in  perfect  alignment.  A  low 
tube  roll  allows  the  stuff  to  run  under  the  deckle  strap  and  make 
a  poor  edge  which  will  break  the  web.  Tube  rolls  that  are 
sprung  cause  the  rolls  to  wabble  and  run  eccentric.  This  action 
makes  bar  marks,  or  thick  and  thin  streaks  across  the  web. 

Tube  rolls  must  not  be  allowed  to  stop  and  wear  flat.  Drag¬ 
ging  over  a  dead  tube  roll  wears  the  wire,  and  it  also  spoils  the 
roll. 

Tube  rolls  must  always  be  handled  very  carefully.  Tube 
rolls  that  are  properly  made  are  carefully  balanced;  if  they 


350  MODERN  PULP  AND  PAPER  MAKING 

are  roughly  handled,  denting  them  or  springing  the  journals  the 
least  bit,  it  throws  the  rolls  out  of  balance  and  they  will  not  run, 
but  even  if  they  do,  they  will  not  run  true,  but  with  an  eccen¬ 
tric  motion,  the  results  of  which  have  been  already  mentioned. 

In  changing  a  wire,  workmen  in  their  haste  are  apt  to  become 
careless  and  often  inexperienced  help  may  be  called  in  from  the 
Beater  Room  to  assist,  who  not  realizing  the  importance  may 
do  considerable  damage. 

For  the  changing  of  wires  many  mills,  especially  the  larger 
concerns,  have  a  well  trained  and  well  organized  crew  who  do 
nothing  else  except  repairs  and  changing  wires,  jackets  and  felts. 
This  plan  saves  money  and  time,  also  accidents  to  the  machin- 
ery. 

Deckle  Straps:  Poor  deckle  straps  with  cracked  edges, 
crooked  places,  worn  edges  and  poor  splices,  uneven  spots  and 
projections  should  be  avoided. 

The  deckle  strap  is  nothing  more  or  less  than  a  dam  against 
which  the  paper  stuff  forms,  and  a  strap  having  any  of  the  above 
mentioned  defects  will  form  an  edge  to  the  web  of  paper  that 
will  not  safely  run  through  the  machine. 

A  cracked  edge  in  a  deckle  strap  will  cause  lumps  and  pro¬ 
jections  to  form  in  the  edge  of  the  web  and  it  will  very  likely 
break  either  on  the  couchers  or  presses. 

Crooked  places  in  the  deckle  strap  are  caused  by  hanging  a 
spare  strap  up  in  a  dry  place  and  allowing  it  to  stay  in  one  posi¬ 
tion  for  so  long  that  the  rubber  becomes  slightly  vulcanized  and 
becomes  set.  A  strap  with  this  defect  will  not  fit  the  wire 
closely  and  allows  stuff  to  run  under  it  making  a  bad  edge  on  the 
web  which  often  causes  breaks. 

Worn  edges  on  the  strap  to  the  extent  that  they  become 
rounded  will  also  make  a  poor  edge  on  the  web. 

Poor  splices  refers  to  the  strap  coming  apart  in  the  splice. 
With  reference  to  this  particular  defect,  it  sometimes  happens 
that  the  splice  made  in  the  strap  is  not  stuck  together  so  but 
what  it  will  eventually  come  apart  for  a  little  distance  at  the 
beginning  of  the  splice.  The  coming  apart  of  the  splice  in  the 
deckle  strap  is  frequently  avoided  by  being  careful  to  put  the 
deckle  strap  on  so  that  the  influence  of  the  wire  on  the  strap 
in  pulling  it  around  will  pull  from  the  splice  instead  of 
against  it. 

Uneven  spots  and  projections  on  a  deckle  strap  are  caused 
by  various  things.  Care  should  always  be  taken  with  deckle 
straps  when  putting  on  wires,  whether  the  deckle  straps  have  to 
be  taken  off  entirely  and  laid  away,  or  whether  they  are  lifted 
with  the  deckle  frame.  If  taken  up  with  the  deckle  frame,  it  is 
necessary  to  tie  the  strap  up  in  places  where  it  sags  so  that  it 
will  not  be  in  the  way.  In  doing  this  they  should  never  be  tied 
with  a  small  hard  string,  as  this  dents  the  strap  and  sometimes 
these  dents  will  not  come  out  for  a  long  time.  A  piece  of  woolen 


THE  MACHINE  ROOM  351 

felt  3  inches  or  4  inches  wide  should  be  used.  This  is  soft  and 
pliable  and  will  never  dent  the  edge  of  the  strap. 

It  should  also  be  borne  in  mind  that  hanging  straps  over 
sharp  projections  like  the  edge  of  the  deckle  frame  should  be 
avoided.  This  will  also  nick  straps  on  the  edge  and  if  left  too 
long  will  cause  indentures  which  may  not  come  out  for  some 
time. 

All  of  these  little  defects  in  the  edge  of  the  strap  will  cause 
like  imperfections  in  the  edge  of  the  web  of  paper,  which  may 
lead  to  breaks. 

A  spare  deckle  strap  should  never  be  hung  up  in  a  dry  place, 
even  if  hung  over  the  proper  circles,  because  the  rubber  in  these 
straps  will  become  slightly  vulcanized  and,  where  they  go  over 
the  circles  they  will  conform  to  that  particular  shape,  which  will 
not  come  out  when  the  strap  is  put  on  to  be  run. 

The  old-fashioned  way  used  to  be  to  hang  straps  up  on  a 
prepared  form  of  this  sort  with  the  idea  that  the  strap  would 
be  turned  around  a  few  inches  every  day,  but  this  method  is 
so  apt  to  be  neglected  that  it  is  not  wise  to  keep  the  strap  in 
this  way.  The  best  way  is  to  keep  them  in  a  box  immersed  in 
water,  the  box  having  sufficient  room  so  that  the  strap  will 
not  have  to  be  kinked  or  turned  in  short  circles.  If  cared  for 
this  way  the  strap  will  always  be  fresh  and  good  without  be¬ 
coming  valcanized. 

Suction  Boxes:  .  In  making  light  sheets,  sometimes  the  first 
box  suction  is  closed.  This  box  will  fill  with  water  and  slop  up 
through  the  sheet  and  cause  breaks.  It  is  better  to  lower  the 
box  down  away  from  wire  if  not  needed.  Filings  from  a  dead 
suction  box  dropping  onto  a  wire  are  not  desirable. 

Couches:  The  tension  or  pull  of  the  web  from  couches  to 
first  press  must  be  carefully  adjusted.  If  the  web  is  pulled  too 
hard,  it  will  cause  breaks  on  account  of  pulling  fibres  apart. 
If  this  condition  does  not  cause  breaks  on  felts,  it  may  cause  the 
sheet  to  snap  off  on  the  dryers  and  possibly  not  until  the  web 
reaches  the  calenders  will  it  break.  If  pulled  too  slack  at  the 
couchers,  it  will  cause  wrinkling.  Wet  wrinkles  will  cut  at  the 
calenders.  From  one  press  to  another  the  same  thing  applies. 

Jackets  dirty,  worn,  wrinkled,  twisted,  bagging  or  threadbare 
on  edges  will  cause  trouble.  Doctor  on  top  couch  roll  must  be 
put  down  evenly  on  both  sides.  Must  not  run  jacket  too  wet  or 
too  dry.  If  too  wet  it  is  likely  to  crush;  too  dry,  filings  from 
doctor  likely  to  drop  onto  the  sheet  and  break  it. 

Wires:  Holes,  cracks,  ravelings,  pitch  spots,  wrinkles,  poor 
seams,  slack  edges  and  filled  meshes,  grease  and  slime  spots, 
etc.  These  have  been  discussed  in  connection  with  care  of  the 
wire. 

Dandy  Roll:  Running  the  sheet  too  wet  under  the  dandy 
roll  will  cause  crush  marks.  The  dandy  roll  wallows  or  wades 
in  water,  which  causes  a  crushed  or  cloudy  appearance  in  the 


352  MODERN  PULP  AND  PAPER  MAKING 

sheet.  It  depends  on  the  cause  of  too  much  water  running 
across  the  suction  boxes  and  under  the  dandy,  how  it  can  be 
corrected.  If  the  suction  boxes  are  wide  open  and  at  the  same 
time  there  is  more  water  than  is  necessary  to  properly  close 
the  sheet,  some  of  the  supply  of  water  may  be  shut  off,  at  the 
same  time  lowering  the  slices. 

If  the  stuff  is  short  and  slow,  it  may  be  difficult  to  stop  the 
crushing.  Very  slow  stuff  necessitates  carrying  the  slices  very 
low  and  the  use  of  as  little  furnish  water  as  possible,  and  yet 
the  sheet  may  run  so  wet  across  the  suction  boxes  and  in  under 
the  dandy  roll  as  to  make  it  impossible  to  run  a  dandy  roll  without 
crushing. 

It  is  never  intended  to  prepare  stuff  that  is  so  slow  as  to 
cause  troubles  of  this  nature,  but  sometimes  things  slip  in  the 
beater  room.  An  accident  on  the  paper  machine  may  hold  up 
the  dumping  of  a  beater  of  stuff  for  hours  after  it  is  ready  to 
dump  into  the  stuff  chests.  In  such  cases  the  stuff  is  likely  to 
slop  and  slush  around  in  the  beaters  an  unreasonable  length  of 
time,  which  always  makes  the  stuff  slippery  and  slow.  Some 
mills  may  not  be  equipped  with  beaters  that  can  be  stopped  when 
the  stuff  is  ready  to  go  to  the  chests.  Sometimes  the  beaters 
may  be  furnished  with  slow  stock  without  the  beaterman  being 
aware  of  this  fact.  If  the  beaters  are  furnished  with  this  stock, 
and  there  is  no  way  provided  for  the  stopping  of  the  beaters 
when  the  stuff  reaches  the  correct  stage,  there  is  no  way  to 
run  it  on  the  machine  with  any  degree  of  success  at  a  speed  con¬ 
sistent  with  the  weight  of  the  sheet.  Cutting  out  white  water 
and  substituting  clear  fresh  water  may  help  some.  Heating 
the  water  or  stuff  may  also  help  in  these  extreme  cases,  but 
it  is  wasteful  and  not  good  workmanship  and  should  be 
avoided. 

If  the  sheet  is  run  too  dry  the  dandy  merely  walks  on  it  and 
many  times  does  what  is  termed  by  paper  makers  as  “licking  up.” 
It  picks  up  the  sheet  from  the  wire  in  places,  sometimes  to  the 
extent  of  making  holes  and  causing  breaks,  but  many  times 
these  spots  are  only  lifted  slightly  by  the  dandy  and  they  drop 
back  into  place,  causing  a  blemish  in  the  sheet  which  resembles 
a  blister.  The  dandy  when  run  on  a  dry  sheet  has  no  smoothing 
or  pressing  effect  and  does  more  harm  than  good,  therefore  the 
amount  of  water  in  the  sheet  under  the  dandy  roll  must  be  cor¬ 
rect,  constant  and  uniform.  This  is  especially  important  in  mak¬ 
ing  water  marks.  The  sheet  must  be  plastic  and  yielding  enough 
to  take  a  deep  and  clear  impression  of  the  water  mark. 

The  Hand  of  a  Paper  Machine. 

When  standing  at  the  winder  and  looking  towards  the  screens 
if  the  drive  is  on  the  right-hand  side  the  machine  is  a  right-hand 
.machine. 

Conversely,  if  when  standing  at  the  winder  and  looking  to- 


THE  MACHINE  ROOM 


353 

wards  the  screens  the  drive  is  on  the  left-hand  side,  the  machine 
is  a  left-hand  machine. 

Save-alls. 

Save-alls  for  paper  and  pulp  mills  are  precisely  what  the 
name  implies.  They  are  intended  to  save  all  of  the  fibres  left 
in  the  white  water,  before  it  passes  to  the  sewer  and  to  waste. 

There  are  many  types  of  save-alls.  The  oldest  type  is  very 
similar  to  a  decker ;  a  cylinder  covered  with  fine  wire  is  immersed 
in  a  vat  of  white  water,  suction  is  applied  and  the  fibres  in  the 
water  cleave  to  the  surface  of  the  cylinder  and  later  in  its  revo¬ 
lution,  a  soft  couch' roll  is  brought  in  contact  with  the  fibres 
adhering  to  the  surface  of  the  cylinder  which  are  picked  up  by 
the  couch  and  at  a  certain  part  of  its  revolution  scraped  from 
the  couch  by  a  wooden  doctor  blade,  which  is  in  gentle  contact 
with  surface  of  the  couch.  The  fibres  of  pulp  through  this 
process  form  a  thick  mush  which  falls  from  the  doctor  into  a 
convenient  mill  box  truck.  The  pulp  thus  collected  can  be 
shoveled  or  forked  into  the  beater. 

The  above  type  of  save-all  has  only  a  natural  suction,  i.  e.,  a 
suction  due  to  the  difference  in  the  head  of  water  inside  and 
outside  of  the  cylinder.  If  a  cylinder  of  the  above  type  is  put 
into  a  vat  of  clear  water,  there  will  be  no  suction,  as  the  clear 
water  will  seek  a  common  level  through  the  meshes  of  the  wire, 
but  if  put  in  a  vat  containing  fibres  of  pulp,  the  water  will  be  pre¬ 
vented  from  reaching  a  common  level,  due  to  the  fibres  partly 
sealing  the  meshes  of  the  wire  (a  revolving  dam)  which  backs 
up  the  water  several  inches  higher  on  the  outside  of  the  cylinder 
than  the  water  on  the  inside  of  the  cylinder,  therefore  the  so- 
called  suction,  which  is  not  an  induced  suction. 

Another  type  of  save-all  is  the  induced  suction  or  pneumatic 
type.  A  cylinder  is  placed  in  a  vat  of  water  containing  fibres 
of  pulp  and  by  means  of  a  suction  pump  connected  to  air  tight 
chambers  which  communicate  with  the  surface  of  the  cylinder 
(at  such  times  as  the  suction  chambers  are  immersed  in  the 
water  during  its  revolution)  a  suction  is  induced,  which  pulls 
the  fibres  onto  the  wire  mesh.  At  a  certain  point  in  the  revo¬ 
lution  of  the  cylinder  these  suction  chambers  become  pressure 
chambers,  and  %  means  of  a  blast  of  air  the  pulp  is  blown  from 
the  cylinder  surface.  This  type  of  machine  is  also  used  for 
thickening  pulp. 

Unless  the  wire  which  covers  the  surface  of  the  cylinder  is 
of  very  fine  mesh,  very  little  of  the  very  fine  fibres  or  fillers  such 
as  clay,  etc.,  is  saved.  Some  manufacturers  have  thought'  it 
worth  while  to  use  save-alls  of  the  settling  tank  type.  These 
settling  tanks  must  be  of  very  large  proportions  to  take  care  of 
all  the  white  water  from  a  pulp  or  paper  mill.  The  capacity 
must  be  such  that  it  permits  of  the  water  standing  long  enough 
to  settle  in  the  bottom  of  the  tanks  from  which  point  the  settled 


Courtesy:  Improved  Paper  Machinery  Co.,  Nashua,  N.  H. 

Fig.  140. — Pneumatic  save-all  showing  manner  in  which  the  mould  is 
divided  into  compartments  for  the  alternate  application  of  suction 
and  pressure. 

This  method  permits  the  savings  being  pumped  back  into  the 
system  without  the  extra  labor  required  in  the  case  of  the  first 
mentioned  classes  of  save-all,  where  the  savings  are  of  such  a 
consistency  that  they  must  be  shoveled  or  forked  into  the  beaters. 
The  settling  tank  must  be  of  ample  capacity  to  effect  a  continu¬ 
ous  operation,  i.e.,  so  that  the  white  water  may  be  running  in  at 
the  top  of  the  tanks,  at  the  same  time  the  settlings  are  being 
pumped  from  tbe  bottom ;  these  tanks  do  not  function  until  they 


354  MODERN  PULP  AND  PAPER  MAKING 


fibres  and  fillers  are  pumped.  The  white  water  is  distributed 
by  means  of  an  annular  trough,  running  around  the  entire  cir¬ 
cumference  of  the  tank  so  that  when  it  finally  reaches  the  tank 
there  is  no  velocity.  This  is  to  prevent  agitation  and  allow  the 
stuff  to  settle  at  the  bottom,  in  the  same  way  that  a  sample  of 
it  will  settle  in  a  bottle  or  glass  jar. 


355 


THE  MACHINB  ROOM 

become  full  of  white  water,  for  then  the  incoming,  supply  flows 
lazily  and  comes  to  rest  on  top  of  this  body  of  water  and  begins 
to  settle  immediately. 

Still  another  type  of  save-all  extracts  the  fibres  from  the 
white  water  by  means  of  centrifugal  force.  This  method  em¬ 
braces  many  desirable  advantages  such  as  permitting  of  pump¬ 
ing  the  savings  back  to  the  system,  instead  of  by  manual  labor, 
low  first  cost,  ample  capacity,  low  up-keep  cost,  self-cleaning 
and  very  low  horse  power  for  operating. 

A  cone  19  inches  diameter  at  small  end  flaring  to  10  feet  at 
large  end,  7  feet  high,  is  stepped  in  a  bearing  with  the  small  end 


Fig.  141. — Witham-McEwen  save-all  as  installed  in  paper  mill. 


of  the  cone  downward  (like  a  spinning  top)  and  two  spiders  are 
keyed  to  a  shaft,  which  passes  through  the  center  of  the  cone. 
The  spider  at  the  apex  is  19  inches  inside  diameter.  The  spider 
at  the  center  is  4  feet  in  diameter.  The  rims  of  both  these 
spiders  are  on  an  angle  or  flare  that  coincides  with  the  slope  of 
the  cone.  The  shaft  passing  through  the  center  of  the  cone, 
protrudes  through  the  small  end  and  is  stepped  in  a  box  (similar 
to  stepping  a  water  wheel).  This  same  shaft  protrudes  at  the 
upper  end  of  the  cone  for  applying  a  gear  or  pulley  for  driving 
or  spinning  the  cone.  Hardwood  staves  are  bolted  to  the  spiders 
at  intervals;  complying  with  the  distance  needed  for  fastening 
suitable  screen  plates.  Screen  plate  sections  with  very  large 
perforations  are  screwed  to  the  inside  of  the  staves.  They  are 
cut  on  an  angle  so  that  the  border  of  each  plate  makes  a  butt 
joint  coming  together  on  each  stave.  Thus  the  entire  inner  sur- 


356  MODERN  PUtP  AND  PAPER  MAKING 

face  is  lined  with  foundation  plates  in  a  way  that  permits  of  a 
smooth  surface  being  presented  to  the  white  water  and  fibre  ma¬ 
terial. 

On  top  of  the  foundation  plates  is  fastened  a  very  fine 
mesh  wire,  the  fineness  of  the  wire  being  determined  by  the 
class  of  saving  it  must  perform.  The  finer  the  wire  the  finer  the 
savings.  The  cone  also  has  a  vertical  annular  rim  6  inches  to  12 
inches  high  which  prevents  the  water  from  slopping  over  into 
the  compartment  between  the  outside  shell  or  housing,  which  en¬ 
circles  the  cone,  placed  within  this  annular  rim  and  clearing  it 
two  inches  all  around  is  a  stationary  solid  head.  On  this  head 
is  also  an  annular  rim.  This  head  is  adjusted  to  water  level 


Fig.  142. — Witham-McEwen  save-all  as  installed  in  sulphite  pulp  mill. 


and  the  white  water  is  spilled  on  this  stationary  head,  which  fills 
up  and  runs  over  the  annular  rim,  which  is  about  4  inches  high, 
causing  the  water  to  flow  and  distribute  evenly  all  around  the 
entire  circle,  falling  against  the  sides  of  the  revolving  cone. 
The  water  is  thrown  through  the  wire  mesh  by  centrifugal  force, 
while  the  savings  slip  down  the  incline  of  the  cone  into  a  com¬ 
partment  directly  under  the  small  end,  to  which  a  centrifugal 
pump  is  connected ;  from  this  point  the  savings  are  pumped 
back  into  the  system;  surrounding  the  cone  is  a  water  tight  shell 
usually  made  of  tongue  and  grooved  sealing,  placed  at  a  suit¬ 
able  distance  from  the  cone.  This  shell  or  housing  may  be 
square,  octagonal  or  round.  It  may  or  may  not  follow  the  lines 
and  shape  of  the  cone. 

It  will  be  seen  that  both  the  rejections  and  savings  may  be 
either  pumped  or  run  to  waste  as  the  case  may  require.  In  case 
this  apparatus  is  used  for  water  straining  or  filtering  purposes, 
the  clean  water  which  is  thrown  through  the  meshes  of  the  wire. 


I . 


357 


Fig.  143. — Diagram  showing  complete  installation  of  Witham-McEwen  save-alls  as  installed  for  water  filtering  at  large  pulp 

and  paper  mill._ 


358  MODERN  PULP  AND  PAPER  MAKING 

may  be  pumped  through  the  water  system  which  serves  the  mill, 
while  the  savings  which  in  this  case  will  be  dirt,  slip  down  the  in¬ 
cline.  of  the  cone  and  to  waste.  It  will  be  seen  that  this  save-all 
can  be  used  for  either  saving  pulp  fibres  or  for  filtering  water, 
without  making  any  change  in  its  construction.  The  shape,  speed 
and  angle  of  the  cone  renders  it  self-cleaning.  There  is  always 
enough  water  sliding  down  the  incline  of  the  cone  to  keep  the  fil¬ 
tering  wire  clean.  A  vertical  shower  pipe  is  placed  adjacent  to  the 
cone  and  between  the  shell  and  the  cone  and  following  the  slant  of 
the  cone,  so  that  by  opening  a  valve,  the  cone  may  be  thoroughly- 
showered,  as  it  revolves,  passing  this  fixed  shower  pipe.  This 
is  in  case  the  meshes  become  filled  up  with  sediment  of  any  kind. 
In  case  of  these  save-alls  being  used  as  filters  their  capacity  is 
nearly  unlimited.  One  of  these  machines  will  filter  two  million 
gallons  in  24  hours  and  will  free  water  from  all  solid  impurities, 
supplying  absolutely  clean  water  for  paper  machine  showers  and 
the  like ;  in  case  they  are  used  as  a  save-all  the  capacity  is 
nearly  as  great. 

The  many  desirable  features  of  these  machines  and  their 
adaptation  to  paper  and  pulp  mill  requirements  should  be  at- 
trative ;  3  horse  power  is  ample  for  one  save-all ;  they  need  no 
supervision. 

The  only  thing  that  wears  is  the  inside  fine  mesh  wire  and 
this  is  only  exposed  to  the  slipping  of  the  water  and  fibres 
down  its  surface. 


Typical  Specifications  for  Paper  Machines. 

CONTRACT  SPECIFICATIONS 


FOR 

ONE  (i)  166"  FOURDRiNIER  NEWS  PAPER  MACHINE. 
To  Be  Built  By 


(Name  of  Company) 


Hand. 


(Address) 

Date 


Contract  No. 
Estimate 


When  standing  at  the  winder  and  looking  toward  the  Fourdrinier,  the 
driving  arrangement  of  the  machine  will  be  on  the  left  hand  side  or 
right  hand  side,  as  decided  by  the  Purchaser. 


Widths. 

Breast  Roll  will  be . 166  inches  face 

Table  Rolls  will  be . 166  inches  face 

Lower  couch  roll  will  be . 166  inches  face 

Lower  press  rolls  will  be . 164  inches  face 

Drying  cylinders  will  be . 162  inches  face 

Calender  rolls  will  be . 160  inches  face 

Reel  drums  will  be . 164  inches  face 

Slitter  and  winder  will  be . 160  inches  face 


I5ff^ 


15 10 1/^ 


20  hR  10  tR  75/f. 


jS  hP.  75/P  135  tP  75^  ffio^vP/TS  p/<j£:sr£ff^i:^  TO^emg:  Pqqci  ^/i^//oosc 


Diaeram  showing  progress  of  material  through  a  typical  pulp  mill  from  the  river  and  saw  mill  to  the  beater  room.  For  convenience  in  arrangement,  the 
earlier  portion  of  *is  flow-sheet  is  inserted  in  the  upper  right-hand  corner.  The  approximate  power  required  in  each  operation  is  indicated  on  the  diagram. 


jical  modern  Fourdrinier  Paper  Machine.  For  convenience  in  arrangement, 
nent  shows  that  portion  of  the  machine  from  the  screens  to  the  third  press,  ’ 


THE  MACHINE  ROOM 


359 


Flow  Box  and  Apron. 

The  design  of  the  flow  box  will  embody  the  features  of  economy  of 
space  and  the  proper  distribution  of  the  pulp  upon  the  apron.  The  flow 
box  will  be  made  of  cypress  wood,  and  will  be  put  together  in  a  sub¬ 
stantial  and  workmanlike  manner.  Design  to  be  approved  by  the  Pur- 
ch^sct** 

The  apron  is  to  be  made  of  wood,  carried  on  wooden  folding  brackets, 
attached  to  the  flow  box;  to  be  compact  in  form,  strong  and  stiff,  and 
provided  with  adjustable  and  fixtures  of  brass. 

Wire. 

The  arrangement  of  the  fourdrinier  part  will  be  suitable  for  a  wire 
8o  feet  long,  and  164  inches  wide. 

Breast  Roll. 

The  breast  roll  will  be  18  inches  diameter,  166  inches  face,  body  made 
of  a  shell  of  cast  gun  metal,  bored  on  inside,  secured  to  cast  iron  heads. 
The  journals  or  gudgeons  of  the  roll  to  be  made  of  hammered  steel  and 
forced  in  the  heads  by  hydraulic  pressure.  Heads  to  have  brass  covers 
and  ends  of  gudgeons  to  be  covered  with  ornamental  brass  sleeve  outside 
of  bearings.  This  design  makes  a  roll  of  minimum  weight,  yet  of 
maximum  strength  and  stiffness.  Journals  carried  in  bronzed  bearings 
having  vertical  adjustment. 

Roll  to  be  running  balance  for  a  speed  of  700  feet  per  minute. 

Table  Rolls. 

The  table  rolls  located  next  to  the  breast  roll  and  under  the  slices, 
will  be  6  inches  diameter,  166  inches  face.  Made  of  turned  steel  tubing 
encased  with  No.  14  S.  W.  G.  brass  tube,  having  cast  iron  heads  with 
steel  journals,  inches  diameter,  zVa  inches  long.  ^  ,  r 

All  the  other  table  rolls  will  be  5V2  inches  diameter,  162  inches  face, 
made  of  brass  tubing  No.  10  S.  W.  G.  having  cast  iron  heads  with  steel 
journals,  inch  diameter,  3^  inches  long. 

All  table  rolls  to  be  in  running  balance,  as  indicated  by  a  Norton 
Balancing  Machine,  at  a  speed  of  700  feet  per  minute. 

Patented  extruded  brass  table  bars  will  support  brass  pintle  yoke 
brackets  to  carry  the  brass  bearings  of  enclosed  type  having  grease 
reservoirs  and  lids,  to  carry  the  table  rolls,  and  will  be  arranged  to  give 
vertical  adjustment  of  the  rolls.  The  bearings  removable  with  the  rolls 

when  changing  wire.  _  ,  ,  1  ^ 

The  table  bars  will  also  be  fitted  with  brass  screws  and  lock  nuts,  so 
arranged  that  the  screws  will  come  against  the  ends  of  the  journals  of 
the  table  rolls,  thus  taking  the  end  thrust,  and  eliminating  the  fnction 
that  would  otherwise  occur  from  contact  of  the  shoulders  of  the  I'olls 
against  the  ends  of  the  bearings,  thereby  preventing  undue  wear  on  the 
wire  and  the  rolls,  that  otherwise  would  be  caused  by  excessive  endwise 
movement  of  the  rolls. 

Automatic  Guide  Roll. 

The  automatic  guide  roll  will  be  10^  diameter,  made  of  turned  steH 
pipe  encased  with  No.  14  S.  G.  brass  tube,  having  cast  iron  heads  with 
steel  journals  carried  in  M.  &  W.  No,  5  patented  automatic  wire  guide 
with  patented  lever  palm  attached  to  work  in  contact  with  one  side 

The  roll  to  be  in  running  balance  as  indicated  by  a  Norton  Balancing 
Machine,  at  a  speed  of  700  feet  per  minute. 

Return  Wire  Rolls. 

Stretch  roll  10^  inches  diameter,  all  other  return  wire  rolls  qH  and 
854  inches  diameter.  These  rolls  to  be  made  of  turned  steel  pipe  encased 


36o  modern  pulp  AND  PAPER  MAKING 

with  No.  14  S.  W.  G.  brass  tube,  having  cast  iron  heads  with  steel  journals, 
2  7/i6"xi3",  2  3/i6"xi3"  and  i  is/i6"xi3",  carried  in  bronze-lined,  collar 
oiling  bearings,  carried  in  supports  in  such  a  way  that  the  bearings  are 
removed  with  the  roll,  in  placing  new  wire  on  the  Fourdrinier. 

The  rolls  will  be  in  running  balance  as  indicated  by  a  Norton  Balancing 
Machine,  at  a  speed  of  700  feet  per  minute. 

Wire  roll  nearest  breast  roll  arranged  to  be  easily  removable. 

The  vertical  stretcher  will  be  so  geared  that  both  sides  may  be 
operated  simultaneously  or  the  back  side  independently,  by  a  hand  wheel 
on  front  side  of  machine.  The  bearings  for  the  stretch  roll  designed 
to  permit  the  weight  of  the  roll  to  act  as  the  stretching  pressure. 

Ductors. 

Wooden  ductors  arranged  on  the  outside  return  wire  rolls. 

Couch  Rolls. 

Upper  couch  roll  26  inches  diameter,  170  inches  face. 

Lower  couch  roll  26  inches  diameter,  166  inches  face. 

The  upper  roll  will  have  a  casing  Yz  inch  thick,  of  special  quality 
gun  metal  bronze,  forced  by  hydraulic  pressure  over  a  hollow  cast  iron 
body,  having  cast  iron  heads  and  hammered  steel  journals;  the  body 
having  been  turned  in  balance,  and  made  as  light  as  is  consistent  with 
proper  strength  and  stiffness.  The  journals  forced  by  hydraulic  pressure 
in  the  heads  and  the  heads  bolted  into  the  ends  of  the  bodies.  Journals 
7  inches  diameter,  ii  inches  long.  Ornamental  brass  caps  to  cover  ends 
of  gudgeons  outside  of  bearings.  Upper  roll  to  be  drilled  to  suit  pur¬ 
chaser. 

The  lower  roll  will  have  a  casing  Yz  inch  thick;  of  special  quality  gun 
metal  bronze,  forced  by  hydraulic  pressure  over  a  hollow  cast  iron  body 
having  cast  steel  heads  and  journals,  the  body  having  been  turned  in 
balance.  The  combined  heads  and  journals  forced  by  hydraulic  pressure 
in  the  ends  of  the  body.  Journals  9  inches  diameter,  14  inches  long. 
Ornamental  brass  caps  to  cover  end  of  journal,  outside  of  bearings  on 
tending  side,  and  half  lug  clutch  fitted  to  journal  outside  of  bearing  on 
driving  side  for  driving  purposes. 

Rolls  to  have  center  collar  oiling  and  center  thrust  rings. 

Couch  Housings  and  Pedestals. 

The  journals  of  the  upper  roll  will  be  carried  in  bronze-lined  pedestals 
attached  to  ball  crank  swinging  arms  in  a  way  to  admit  of  variation  for 
different  amounts  of  couch.  The  pedestals  will  be  connected  to  a  system 
of  levers  and  weights,  so  as  to  properly  distribute  the  weight  over  the 
entire  surface  of  the  journals,  thus  giving  additional  pressure  to  the 
weight  of  the  roll  on  the  paper,  if  so  desired. 

Improved  couch  housings  to  carry  the  bell  crank  swinging  arms.  The 
Housings  arranged  with  geared  brass  screws  operated  by  handwheels  for 
lifting  each  end  of  the  upper  couch  roll  to  give  clearance ‘between  rolls 
for  convenience  in  putting  jacket  on  upper  roll  and  putting  on  new  wire. 

The  Journals  of  the  lower  roll  will  be  carried  in  bronze-lined  pedestals 
on  blocking  pieces,  resting  directly  on  the  side  frames  of  the  machine, 
arranged  so  that  the  wire  can  be  put  on  without  lifting  the  lower  roll 
more  than  inch,  and  without  removing  pedestals.  Blocking  pieces 
removable. 

The  pedestals  for  both  the  upper  and  lower  rolls  will  be  water-cooling 
and  collar-oiling. 

Guard-Board. 

Very  heavy  and  well  braced  and  held  in  position  by  cast  iron  brackets 
on  the  couch  arms.  Guard-board  arranged  with  a  series  of  adjustable 
spring  fittings  to  give  flexibility  and  adjustability  to  the  guard-board 
blade. 


THE  MACHINE  ROOM 


361 


Dandy  Roll. 

One  wove  dandy  roll  13  inches  diameter,  166  inches  face,  No.  50  wire 
face,  made  as  light  as  possible;  journals  large  in  diameter  and  made 
hollow  to  suit  an  internal  brass  shower  pipe.  Dandy  roll  to  have  central 
bearing  for  shower. 

Wooden  wiper  bar  and  trolley  for  removing  dandy  roll. 

Adjustable  brass  bearings  so  designed  as  to  enable  the  machine  tender 
to  raise  or  lower  both  ends  of  the  roll  at  the  same  tJfne,  when  standing 
on  either  side  of  the  machine. 

Suction  Boxes. 

Eight  (8)  extruded  metal  suction  boxes  with  expanding  heads.  Hard 
maple  covers,  inches  thick.  A  system  of  pipes  for  priming  both  ends 
of  each  box  to  the  same  water  level,  so  that  the  machine  tender  need  ob¬ 
serve  the  tending  side  of  machine  only.  Outlet  pipes  3^  inches  diameter. 
Side  flanges  to  strengthen  the  box  against  the  pull  of  the  wire,  will  be 

so  arranged  that  they  will  also  form  a  channel  way  to  catch  and  conduct 

beyond  the  outside  edges  of  the  wire,  the  water  and  pulp  that  may  be 

scraped  off  the  underside  of  the  wire  by  the  edges  of  the  suction  box 

covers. 

The  suction  pipes  will  be  connected  to  the  boxes  by  an  improved 
device,  by  means  of  which  the  pipes  are  attached  to,  or  released  from 
the  boxes  by  making  one  turn  of  one  screw.  Suction  pipes  attached  to 
manifold  pipe.  Attachments  to  the  stationary  rails  will  be  furnished,  and 
also  suitable  bars  to  facilitate  the  placing  and  removal  of  the  boxes. 

The  dandy  roll  will  be  placed  so  that  two  suction  boxes  will  be 
between  it  and  the  breast  roll  and  six  suction  boxes  between  it  and  the 
couch  rolls. 

Boxes  to  be  arranged  with  wheels  to  facilitate  removing. 

Deckle  Arrangement. 

A  pair  of  flanged  brass  deckle  pulleys,  28  inches  diameter,  suitable 
for  deckle  straps  2j4  inches  wide,  2>^  inches  deep.  One  brass  slice,  10 
inches  deep  with  center  and  end  adjustment  to  insure  even  thickness  of 
the  sheet  of  paper.  Slices  to  be  placed  over  breast  roll.  Two  patented 
brass  wash  troughs  provided  with  proper  shower  pipes  and  sliders  for 
washing  the  deckle  straps,  and  also  drain  pipes  to  carry  off  the  water. 

The  brass  side  frames  carrying  the  above  equipment  will  be  supported 
by  heavy  brass  tubes  with  special  end  journals,  resting  in  babbitted  brass 
bearings  in  such  a  way  that  the  deckle  frames  and  equipment  can  be 
lifted  from  their  bearings  when  putting  the  wire  on  the  machine.  To 
change  the  deckle  width  of  the  paper,  a  system  of  brass  screws,  rods, 
bevel  gears  and  cranks  will  operate  the  deckle  arrangement  on  both  sides 
of  the  machine  independently,  while  the  machine  is  running. 

To  carry  the  return  ends  of  the  deckle,  there  will  be  a  pair  of  brass 
wheels  28  inches  diameter,  8  inches  face,  mounted  on  a  tubular  brass 
shaft  carried  in  adjustable  brass  bearings,  that  will  permit  of  the  easy 
removal  of  the  shaft  and  wheels.  Bearings  to  have  ample  take-up.  To 
secure  the  brass  wheels  to  the  shaft  there  will  be  a  quick  clamp  device 
that  can  be  operated  by  hand,  for  the  easy  adjustment  of  deckles  to  suit 
different  widths  of  paper. 

Intermediate  deckle  support,  gallows  frame  type,  will  be  placed  between 
the  wash  trough  and  the  return  deckle  wheels,  to  prevent  excessive  sag 
of  the  deckle  straps. 

Shake  and  Stationary  Rails. 

The  shake  and  stationary  rails  will  be  of  steel,  brass  cased;  the  shake 
rails  9  inches  wide,  2  inches  deep,  ^nd  the  stationary  rails  8  inches  wide, 
S  inches  deep, 


362  MODERN  PULP  AND  PAPER  MAKING 

The  shake  rails  will  carry  the  deckle  frames  and  table  rolls,  and 
stationary  rails  the  return  deckle  wheels,  dandy  roll  and  suction  boxes. 

Save-all  Boxes. 

Located  under  the  table  rolls  which  are  nearest  to  the  breast  roll 
and  made  in  one  section  of  sheet  brass,  of  strong  design,  having  sides 
of  the  triangular  girder  type.  Carried  by  hollow  cast  iron  stand  at  each 
side  of  the  machine.  The  stand  on  the  tending  side  will  be  provided  with 
an  iron  roller  for  the  easy  removal  of  the  cross  save-all. 

This  save-all  will  discharge  the  water  which  falls  into  it,  through 
openings  in  the  ends  of  the  box,  front  and  back,  and  through  the  hollow 
stands  into  the  concrete  pit  under  the  Fourdrinier  part. 

Suitable  porter  bars  for  handling  this  save-all  will  be  furnished. 

Water  Pipes  and  Showers. 

A  complete  system  of  galvanized  iron  water  pipes,  comprising  two 
6  inch  pipe  sections,  provided  with  an  8  inch  inlet  tee  and  with  branch 
connections  to  the  shower  pipes,  fill  pail,  suction  boxes,  hose  and  water  jet. 

The  branches  will  be  provided  with  straightway  shut-off  valves,  and 
with  brass  fitted  unions,  located  beyond  the  shut-off  valves. 

There  will  be  four  brass  shower  pipes  2^4  inches  diameter,  for  the 
returning  wire,  one  brass  nozzle  spray  shower  2  inches  diameter  over 
the  flow  box,  one  nozzle  spray  shower  2  inches  diameter  at  the  slices, 
one  brass  shower  in  the  dandy  roll,  one  brass  shower  stream  2  inches 
diameter  at  the  guard  board,  and  one  special  brass  shower  2  inches 
diameter,  7  ft.  long,  with  hose  connection  and  trolley  for  each  press 
felt.  Located  between  the  last  suction  box  and  the  guide  roll,  there  will 
be  a  water  jet  for  cutting  the  paper  on  the  wire. 

Shake. 

The  patented  shaking  frame  with  spring  supports,  forming  cantilever 
side  frames  with  the  shake  rails.  Spiral  spring  arrangements  to  take  side 
thrust  of  Fourdrinier  due  to  shake,  thus  relieving  the  shake  head  and 
shaking  frame  from  undue  strain  and  wear. 

The  feet  of  the  frames  of  the  fourdrinier  will  be  so  elevated  by  cast 
iron  tapered  blocks,  that  the  top  of  the  breast  roll  will  be  18  inches  above 
the  top  of  the  guide  roll,  thus  giving  this  amount  of  drop  or  pitch  to  the 
wire. 

Where  the  shake  and  stationary  rails  meet  they  -vvill  be  supported  by 
substantial  steady  frames,  connected  across  the  machine  by  a  heavy  cast 
iron  tie  frame,  thus  preventing  the  shake  motion  being  carried  into  the 
stationary  part  of  the  Fourdrinier. 

Shake  head  of  improved  design  for  shaking  the  Fourdrinier  frame, 
with  heavy  fly  wheel  and  adjusting  crank  pin  for  varying  the  shake,  and 
with  a  registering  dial  to  accurately  determine  and  record  the  amount  of 
shake.  Sleeve  with  pulley,  24  inches  diameter,  6  inches  face,  with  friction 
clutch  attached  for  starting  and  stopping  the  shake.  Sprocket  wheel  and 
drive  to  same,  furnished  by  Purchaser. 

Fan  Pump. 

One  (i)  8"  fan  or  centrifugal  pump,  for  the  white  water  trom  the 
Fourdrinier  part.  Pump  casing  or  shell  to  he  halved  in  such  manner  as 
to  permit  the  fan  to  be  exposed  without  disturbing  the  pipes  or  shaft. 
Casing  also  to  be  provided  with  a  hand-hole  and  cover. 

The  pump  case  housings  and  the  two  cast  iron  ring-oiling  shaft  bear¬ 
ings  to  be  mounted  on  a  heavy  cast  iron  base  plate,  thus  making  the  pump 
self  contained. 

The  piping  to  and  from  the  fan  pump  is  not  included  in  these 
specifications. 


THE  MACHINE  ROOM 


363 


Press  Rolls. 

First  press,  upper  roll,  26  inches  diameter,  168  inches  face,  wood. 

First  press,  lower  roll,  26  inches  diameter,  164  inches  face,  rubber 
covered. 

Second  press,  upper  roll,  26  inches  diameter,  168  inches  face,  wood. 

Second  press,  lower  roll,  26  inches  diameter,  164  inches  face,  rubber 
covered. 

Third  press,  upper  roll,  24  inches  diameter,  165  inches  face,  gun  metal 
cased. 

Third  press,  lower  roll,  26  inches  diameter,  164  inches  face,  rubber 
covered. 

The  upper  wooden  rolls  will  be  made  of  sweet  gum  wood,  having 
heads  and  journals  cast  in  one,  and  held  by  a  large  diameter  center  rod 
through  the  entire  length  of  the  roll.  Journals  7  inches  diameter,  ii 
inches  long. 

The  upper  gun  metal  cased  roll  will  have  casing  inch  thick,  of 
special  quality  gun  metal  bronze,  forced  by  hydraulic  pressure  over  a 
hollow  cast  iron  body  having  cast  steel  heads  and  journals;  the  body 
having  been  turned  in  balance  and  made  as  light  as  is  consistent  with 
proper  strength  and  stiffness.  The  combined  heads  and  journals  forced 
by  hydraulic  pressure  in  the  ends  of  the  bodies.  Journals  7  inches 
diameter,  ii  inches  long.  The  extension  of  the  journal  of  the  upper 
rolls  outside  of  bearing,  on  the  tending  side,  will  be  covered  by  orna¬ 
mental  brass  caps,  and  on  the  driving  side  by  cast  iron  sprocket  caps. 

The  lower  rubber  covered  rolls  will  have  rubber  covering  thick 
over  a  hollow  cast  iron  body,  having  cast  steel  heads  and  journals;  the 
body  having  been  turned  in  balance.  The  combined  heads  and  journals 
forced  by  hydraulic  pressure  in  the  ends  of  the  bodies.  Journals  9  inches 
diameter,  14  inches  long.  The  extension  of  the  journal  outside  of  bear¬ 
ing  on  the  tending  side  will  be  covered  by  an  ornamental  brass  cap,  and 
on  the  driving  side  a  half  lug  clutch  will  be  fitted.  The  rubber  covering 
will  be  of  such  density  and  hardness  as  will  equal  that  of  certain  samples 
of  rubber  chosen  by  the  Purchasers  from  samples  submitted  by  the 
Builders,  or  otherwise,  the  Purchasers  will  accept  the  density  of  hard¬ 
ness  of  rubber  covering  selected  by  the  Builders  in  accordance  with  their 
experience  in  building  machines  of  this  class. 

Rolls  to  have  center  collar  oiling  and  center  thrust  rings. 

Press  Housings  and  Pedestals. 

The  journals  of  the  upper  roll  will  be  carried  in  bronze-lined  bell 
crank  swinging  arms,  connected  to  a  system  of  levers  and  weights  so  as  to 
properly  distribute  the  weight  over  the  entire  surface  of  the  journals, 
thus  giving  aditional  pressure  on  the  weight  of  the  roll  on  the  paper  if 
desired. 

Puseyjones  patented  housings  carrying  the  bell  crank  swinging  arms 
will  be  arranged  with  geared  brass  screws  operated  by  handwheels  for 
lifting  each  end  of  the  upper  press  roll,  to  give  clearance  between  upper 
and  lower  rolls  for  convenience  in  putting  on  press  felt. 

Housings  for  first  and  second  presses  suitable  for  28  inch  upper  roll, 
to  take  care  of  large  diameter  wooden  roll. 

The  journals  of  the  lower  press  roll  will  be  carried  in  bronze-lined 
pedestals  on  blocking  pieces,  resting  directly  on  the  side  frames  of  the 
machine.  The  bearings  for  both  the  upper  and  lower  rolls  will  be  water 
cooling  and  collar  oiling.  The  blocking  pieces  removable  for  changing 
felts. 

Ductors. 

One  vibrating  ductor  for  each  upper  press  roll  with  steel  frames. 
Wooden  ductor  blades  for  the  wooden  upper  rolls  and  hard  rubber  ductor 
blades  for  the  gun  metal  upper  press  roll.  Vibrating  arrangement  com- 


364  MODERN  PULP  AND  PAPER  MAKING 

plete  including  worm  wheel  and  wonu,  and  sprocket  gear  drive  from  ex¬ 
tension  of  upper  roll  journal  on  driving  side. 

One  crumb  catcher  for  each  press. 

Save-alls. 

A  trussed  wooden  save-all  of  proper  form  and  dimensions  will  be 
arranged  under  each  lower  press  roll,  carried  on  cast  iron  brackets  on 
inside  of  press  frames. 

Footboards. 

A  wooden  footboard  with  the  necessary  steps  with  special  treads  and 
supporting  frames,  will  be  arranged  at  each  pair  of  press  rolls. 

Press  Frames. 

Complete  extending  under  the  entire  press  part  and  join  these  under 
the  couchers.  These  main  frames,  of  our  latest  design,  will  support  the 
upper  press  roll  housings,  lower  press  roll  pedestals,  footboard  supports, 
small  stands,  save-all  brackets  and  felt  roll  brackets. 

Water  log  arrangement  in  press  frames  to  take  press  save-all  water. 
Three  sets  of  holes  will  be  arranged  in  the  frames  for  holding  the 
first  and  second  press  housings.  By  using  one  set  of  holes,  the  center  of 
the  upper  press  rolls  can  be  run  directly  over  the  center  of  the  lower  press 
rolls,  or  by  using  the  other  set  of  holes,  the  center  of  the  upper  press 
rolls  can  be  couched  2  and  4  inches  toward  the  Fourdrinier  part.  In  the 
case  of  the  third  press,  two  sets  of  holes  will  allow  the  upper  roll  to  be 
directly  over  the  lower  roll,  or  to  be  couched  2  inches  toward  the  dryers. 

General  Arrangement  of  Felts. 

The  first  and  second  press  felts  will  pass  in  a  forward  direction 
through  their  respective  presses,  and  the  third  press  felt  will  pass  in  the 
reverse  direction  through  its  press.  Arrangement  to  suit  press  felts 
exactly  85  feet  long. 

Felt  Rolls. 

All  the  necessary  press  felt  rolls  will  be  9^4  and  8^4  inches  diameters, 
made  of  turned  steel  pipe,  encased  with  No.  14  S..  W.  G.  brass  tube, 
having  cast  iron  heads  with  steel  journals  2  3/16  in.  by  13  in.  and  i  s/ib  in. 
by  12  in.,  carried  in  bronze-lined  bracket  bearings,  the  journals  extending 
beyond  the  bearings  to  form  handholds  to  facilitate  in  placing  new  felts 
on  the  presses.  The  larger  diameter  felt  rolls  will  be  used  in  the 
places  where  the  strain  of  the  felt  is  greatest,  and  the  smaller  diameter 
rolls  will  be  used  in  the  places  where  the  strain  of  the  felts  is  lightest. 

One  of  these  felt  rolls  for  each  press  felt  will  be  “wormed”  on  the 
face  with  brass  strips,  which  strips  will  be  secured  and  pinned  to  the 
body  of  the  roll. 

Felt  Stretchers. 

One  horizontal  press  felt  stretcher  for  each  felt  so  fitted  with  brass 
gears  and  screws  that,  if  desired,  both  screws  can  be  operated  simultane¬ 
ously,  or  the  screw  on  the  driving  side  independently,  by  a  hand  wheel 
on  the  tending  side  of  the  machine. 

Automatic  Guide. 

One  automatic  guide  for  each  felt,  with  hand  adjustment  on  the 
tending  side. 

Suction  Boxes. 

One  open  type  suction  box,  for  the  first  felt,  and  one  open  type  suction 
box  for  the  second  felt,  made  of  8  inch  diameter  galvanized  iron  pipe, 


THE  MACHINE  ROOM 


365 

with  extruded  brass  edges  where  same  come  in  contact  with  the  felt. 
Suction  boxes  arranged  on  the  lead  of  the  felts  before  entering  the  nip 
of  the  presses. 

Shower  Pipes. 

One  special  brass  shower  pipe  for  each  press  felt,  as  before  mentioned. 
Paper  Rolls. 

The  three  paper  rolls  at  the  third  press  will  be  7^  inches  diameter, 
made  of  brass  tubing  No.  10  S.  W.  G.  having  cast  iron  heads  and  steel 
journals  carried  in  ball  bearing  brackets.  These  three  rolls  will  each 
be  fitted  with  a  fly  wheel  pulley  to  be  driven  by  a  belt  from  a  corre¬ 
sponding  pulley  on  the  end  of  one  of  the  felt  rolls. 

Rolls  to  be  in  running  balance,  as  indicated  by  a  Norton  Balancing 
Machine,  at  a  speed  of  700  feet  per  minute. 

Small  Stands. 

All  necessary  small  stands  and  frames  for  the  general  arrangement 
of  the  press  part. 

Dryers. 

Thirty-two  (32)  cast  iron  paper  dryers,  each  60  incties  diameter,  162 
inches  face. 

The  inside  of  the  shell  of  each  dryer  to  be  bored  and  the  outside 
face  to  be  turned  and  polished.  The  tending  side  head  of  each  dryer  to 
have  a  manhole  fitted  with  specially  designed  manhole  cover.  Journals 
10  inches  diameter,  13  inches  long.  The  extension  of  the  journal  outside 
of  bearing  on  the  tending  side  will  be  covered  by  an  ornamental  brass 
cap  and  on  the  driving  side  keyseated  to  receive  driving  spur  gears. 
Dryers  to  be  balanced. 

One  cast  iron  overhung  paper  dryer,  24  inches  diameter,  162  inches  face. 
This  dryer  which  is  overhung  toward  the  press  part  and  receives  the 
paper  therefrom  will  have  the  outside  face  turned  and  polished.  Journals 
7  inches  diameter,  12  inches  long.  The  extension  of  the  journal  outside 
of  bearing  on  the  tending  side  will  be  covered  by  an  ornamental  brass 
cap,  and  on  the  driving  side  keyseated  to  receive  driving  spur  gear. 
Dryer  to  be  balanced. 

Two  (2)  cast  iron  felt  dryers,  48  inches  diameter,  162  inches  face. 
The  inside  of  the  shell  of  each  dryer  to  be  bored  and  the  outside 
face  to  be  turned  and  polished.  The  tending  side  head  of  each  dryer  to 
have  a  manhole  fitted  with  specially  designed  manhole  cover.  Journals 
qH  inches  diameter,  12  inches  long.  The  extension  of  the  journal  out¬ 
side  of  bearing  on  the  tending  side  will  be  covered  by  an  ornamental  brass 
cap,  and  on  the  driving  side  keyseated  suitable  for  driving  gear,  if  it  is 
found  desirable  to  add  same  later.  Dryers  to  be  balanced. 

One  of  these  dryers  will  be  placed  on  the  return  of  the  first  upper  felt, 
and  the  other  placed  on  the  return  of  the  first  lower  felt  to  help  dry 
these  felts.  They  will  be  arranged  so  that  the  side  of  the  felt  which  comes 
next  to  the  paper  will  be  next  to  the  surface  of  the  dryer. 

Dryers  to  have  center  collar-oiling  and  center  collar  thrust. 

Dryer  Dippers. 

Arranged  in  each  dryer  at  the  driving  side  will  be  an  internal 
duoliptical  dipper  to  remove  the  water  of  condensation  from  the  dryer. 

Air  Valves. 

Hand  operated  brass  air  valves  to  be  placed  on  the  end  of  the  journals 
of  each  dryer  on  the  tending  side  of  machine,  capable  of  being  operated 
while  machine  is  running. 


366  MODERN  PULP  AND  PAPER  MAKING 

Steam  Joints. 

To  the  extension  of  each  dryer  journal  on  the  driving  side  will  be 
fitted  a  patented  combined  steam  joint  and  safety  valve,  arranged  to  admit 
steam  to  the  dryer,  and  connected  by  pipe  to  the  dipper  to  remove  water 
of  condensation  therefrom. 

Cooling  Dryers. 

The  last  upper  and  last  lower  dryer  will  be  arranged  with  a  shower 
pipe  to  uniformly  cool  the  surface  of  the  dryer.  Funnels  arranged  with 
pipe  connections  will  catch  the  overflow  from  ends  of  journals,  both 
front  and  back.  The  standard  equipment  of  dippers,  steam  joints,  piping, 
etc.,  will  be  furnished  for  these  two  dryers,  so  that  they  may  be  installed 
later  if  found  necessary. 

Vertical  and  Horizontal  Piping. 

The  vertical  steam  inlet  pipes  3  inches  diameter  and  the  vertical 
water  outlet  pipes  inches  diameter,  will  connect  at  the  upper  ends  of 
the  steam  joints  above  mentioned,  and  to  the  horizontal  steam  and  water 
pipes  by  improved  clamps.  1  he  horizontal  steam  pipe  will  be  8  inches 
diameter,  and  the  horizontal  water  pipe  4  inches  diameter  and  each  will 
extend  the  full  length  of  the  dry  part.  . 

The  steam  pipe  to  be  divided  into  two  sections,  each  section  having 
at  the  middle  an  8  inch  by  8  inch  by  10  inch  special  distribution  tee. 
A  10  inch  by  10  inch  by  12  inch  distribution  tee  will  also  be  furnished 
which  will  connect  to  the  8  inch  by  8  inch  by  10  inch  distribution  tees 

with  8  inch  piping.  .  ,  ,  ,  a 

The  water  pipes  will  be  divided  into  four  sections  by  blank  flanges, 
each  section  having  a  tee  connection  at  the  middle,  to  which  tees  the 
Purchasers  will  connect  from  steam  traps. 

Each  vertical  steam  pipe  will  be  fitted  with  a  brass  mounted  union 
placed  just  above  the  machine  room  floor.  . 

Dryer  Pedestals. 

Cast  iron  dryer  pedestals  fitted  with  phosphor-bronze  shells  so  de¬ 
signed  that  the  shells  may  be  renewed  without  removing  the  pedestals 
from  the  machine  Pedestals  arranged  for  collar  oiling  and  to  have  cap 
covers. 

Dryer  Frames. 

Cast  iron  dryer  side  frames  will  be  arranged  to  carry  the  pedestals  of 
the  sixteen  dryers  in  the  upper  tier.  Hand  rails  across  the  open  spaces 
between  the  upper  frames  on  tending  side. 

The  pedestals  of  the  sixteen  dryers  in  the  lower  tier  resting  directly 
on  sill  plates  10  inches  high,  which  will  also  carry  the  upper  dryer 

frames.  . 

Frames  for  carrying  the  upper  felt  equipment  and  the  upper  felt 
dryers  will  be  furnished  complete. 

To  carry  the  lower  felt  equipment  on  the  return,  in  the  basement, 
there  will  be  furnished  the  necessary  channel  beams  to  be  attached  to 
the  steel  columns  furnished  by  the  Purchasers,  to  support  the  machine 
foundations. 

Dryer  Gears  and  Pinions. 

The  cast  iron  driving  spur  gears  for  all  the  paper  dryers  will  have 
machine  cut  teeth  2  inches  pitch,  and  hubs  of  the  clamp  design.  All  the 
spur  gears  will  be  5  inches  face,  with  the  exception  of  the  four  spur 
gears  meshing  with  the  driving  pinions,  which  are  to  be  7  inches  (^ce. 
The  two  driving  pinions  will  have  machine  cut  teeth  2  inches  pitch. 
7  inches  face. 

Gear  guards  placed  where  necessary. 


THE  MACHINE  ROOM 


3^7 


Doctors. 

Five  doctors  with  rock  maple  blades  and  spring  tension  arrangement 
to  be  placed  on  the  last  four  lower  dryers  and  the  last  upper  dryer. 

Footboards.  i  u 

An  iron  footboard,  supported  by  cast  iron  columns  will  extend  the 
whole  length  of  the  nest  of  dryers  on  the  driving  side,  and  will  have 
two  flights  of  cast  iron  steps  and  the  necessary  iron  hand  railing.  Also 
a  cast  iron  footboard  supported  by  cast  iron  brackets  at  the  press  end 
of  the  dryers  on  the  tending  side  of  machine. 

General  Arrangement  for  Felts. 

Will  be  for  two  upper  and  two  lower  felts. 

Felt  Rolls. 

All  the  necessary  dryer  felt  rolls  will  be  10^4  and  9j4  inches  diameter, 
made  of  turned  steel  pipe  having  cast  iron  heads  with  steel  journals, 

2  7/i8  in.  and  2  3/18  in.  diameters,  carried  in  bronze-lined  collar  oiling 
bracket  bearings.  The  large  diameter  felt  rolls  will  be  used  in  the  places 
where  the  strain  of  the  felts  is  greatest,  and  the  smaller  diameter  felt 
rolls  be  used  in  the  places  where  the  strain  of  the  felt  is  lightest. 

Guides.  ,  ,  •  1  r 

One  automatic  guide,  one  hand  adjuster  and  one  hand  guide  tor 

each  felt. 

Automatic  Tighteners.  • ,  j 

One  anti-friction  automatic  tightener,  having  horizontal  guides  and 
weight  tension  arrangement  complete. 

Paper  Spring  Roll, 

Located  at  the  end  of  the  nest  of  dryers  to  lead  the  sheet  0/  paper 
to  the  calenders,  will  be  a  spring  roll  10^  inches  diameter,  made  of  turned 
steel  pipe,  having  cast  iron  heads,  with  steel  journals,  2  7/16  inches 
diameter,  carried  in  bronze-lined,  self-oilmg  bearing,  mounted  m  brackets 
by  circles  of  springs  to  allow  for  uneven  tension  of  the  draw  of  paper. 

Roll  to  be  in  running  balance  as  indicated  by  a  Norton  Balancing 
Machine,  at  a  speed  of  700  feet  per  minute. 

C/dlcndcrs. 

One  stack  of  chilled  iron  calender  rolls,  comprising  ten  rolls,  as 
follows : 

One  18  inch  top  roll. 

Seven  13  inch  intermediate  rolls. 

One  12  inch  next  bottom  roll. 

One  28  inch  bottom  roll, 

all  160  inches  face,  with  heavy  S>oei9  pattern  housing.  Housings 

wide  enough  to  permit  the  intermediate  rolls  to  be  taken  out  endwise. 

All  journal  boxes  to  be  babbitted  and  cored  for  water-cooling  and 
those  for  the  bottom  roll  made  self-oiling.  All  necessary  levers  an 
weights  for  applying  pressure  to  the  journals  of  the  top  roll. 

Lift  rods  on  outside  of  housings.  The  strongbacks  rod  to  rod  under 
the  roll  boxes  will  be  of  steel,  and  will  be  carried  by  adjustable  nuts  on 
the  lifting  rods,  which  will  be  operated  by  Farrell  Hydraulic  Lift  and 

hand  pump.  _  .  * 

Brass  chafing  rings  for  intermediate  rolls.  ,  _  , 

Complete  equipment  of  “Warren”  Doctors  and  Feeds. 

The  doctor  for  the  bottom  roll  will  be  placed  apinst  the  side  of  the 
roll  nearest  the  dryers  so  that  in  starting  up,  the  first  run  of  the  paper 
may  be  directed  through  an  opening  in  the  floor. 


368  MODERN  PULP  AND  PAPER  MAKING 

Reel. 

One  (i)  164  inch  Uniform  Speed  Reel,  arranged  with  two  winding 
drums. 

The  driving  drum  is  42  inches  diameter,  the  shell  and  heads  being 
made  of  cast  iron  and  similar  in  design  to  a  dryer  shell.  The  tending 
side  journal  to  be  fitted  with  an  ornamental  brass  cap  and  driving  side 
journal  with  half  lug  clutch. 

The  driving  drum  is  carried  in  bronze-lined  pedestals  which  rest  on 
heavy  cast  iron  frames.  An  extension  arm  on  each  of  these  frames  carry 
a  doctor  having  wooden  blade  and  suitable  equipment  of  bearings,  levers 
and  weights. 

Two  winding  drums  each  inches  diameter  made  of  extra  heavy 
steel  pipe,  turned  on  the  face.  Each  end  of  pipe  to  be  fitted  with  a  cast 
iron  head  into  which  the  steel  journal  is  forced.  Each  journal  is  square 
on  the  end,  to  suit  a  crank,  for  turning  drums  by  hand  when  on  the  un¬ 
winder.  The  tending  side  journal  of  each  drum  is  fitted  with  a  cast  iron 
spur  pinion,  having  machine  cut  teeth,  which  is  used  in  connection  with 
friction  arrangement  on  the  unwinder. 

The  winding  drums  are  carried  in  swinging  arms  having  brass-lined 
bearings  with  caps;  the  bearings  being  adjustable  to  insure  even  con¬ 
tact  on  driving  drums.  Each  set  of  swinging  arms  is  keyed  to  a  cross 
shaft,  this  shaft  being  supported  in  rigid  bearing  on  tending  side  and 
adjustable  bearing  on  driving  side.  For  raising  the  roll  of  paper  from 
the  riving  drum  a  quadrant  mounted  on  cross  shaft  at  tending  side 
engaged  with  a  compound  train  of  gears,  the  bearing  being  operated  by 
a  hand  wheel. 

1  he  hand  wheel  is  equipped  with  a  clutch  device  for  holding  roll  in  a 
given  position.  The  balance  weight  arrangement  may  entirely  or  partially 
relieve  the  back  pressure  of  the  gears  when  winding  paper  on  the  drums. 
Suitable  spreader  bar  to  be  furnished. 

The  maximum  diameter  roll  of  paper  that  can  be  wound  on  this  reel 
is  42  inch. 

Unwinder. 

One  unwinder  of  the  geared  type  to  receive  the  drums  filled  with 
paper  taken  from  the  reel. 

The  unwinder  to  consist  of  one  pair  of  stands  with  bronze-lined  bear¬ 
ings.  The  bearing  on  tending  side  is  equipped  with  screw  and  handwheel 
for  lengthwise  adjustment.  The  tending  side  stand  is  mounted  on  a  base 
and  is  equipped  with  screw  and  ratchet  wrench  for  crosswise  adjustment. 

The  spur  pinion  on  reel  drum  meshes  into  a  spur  gear  having  machine 
cut  teeth,  which  is  keyed  to  a  pin,  the  other  end  of  pin  being  fitted  with 
friction  pulleys.  The  pin  revolves  in  a  brass  bushing  which  is  fitted  into 
hub  on  tending  side  stand.  The  friction  pulley  is  fitted  with  strap,  screw 
and  handwheels  for  applying  pressure. 

The  bearing  cap  on  tending  side  bearing  is  made  with  cover  to  protect 
the  gears. 

With  the  geared  design  of  unwinder  it  allows  the  changing  of  drums 
without  disturbing  the  friction  arrangement,  and  it  also  allows  a  large 
friction  pulley  to  be  used,  this  arrangement  reducing  the  liability  of 
heating  the  friction  straps. 

One  reel  drum  duplicate  of  ones  on  reel  to  be  furnished  for  use  with 
the  unwinder. 

Slitter  and  Winder  (Combined). 

One  (i)  160  inch  slitting  machine,  combined  with  a  160  inch  two- 
drum  uniform  speed  winder,  of  designated  standard  make.  Cast  iron 
drums  16  inches  diameter.  Upper  slitter  bar  4%  inches  diameter.  Lower 
slitter  shaft  yYA  diameter.  Lower  slitter  shaft  to  have  a  center  adjustable 
bearing.  Six  upper  slitters;  six  lower  slitters,  double  edged,  12  inches 


THE  MACHINE  ROOM 


369 

diameter.  The  winding  shaft  will  have  quick  opening  boxes  and  will  be 
arranged  with  threads  and  nuts  to  suit  3  inch  gas  pipe  cores.  Intake 
shafts  connected  to  drums  with  flanged  couplings. 

Drums  to  be  balanced  at  a  surface  speed  of  1500  feet  per  minute. 

Driving  Arrangement. 

Of  the  parallel  rope  type,  beginning  with  a  large  sheave  wheel  with 
grooves  suitable  for  lA  inch  diameter  cotton  ropes,  a  short  heavy  shaft, 
two  ring-oiling,  babbitted,  rigid  pillow  blocks,  and  two  wedge-adjusting 

cast  iron  stands.  ,  ,  1 

Power  is  to  be  supplied  to  this  shaft  and  sheave  by  the  Purchasers, 
who  are  expected  to  couple  direct  to  the  shaft,  a  sufficiently  powerful 
variable  speed  electric  motor  or  engine,  375  revolutions  of  which  will 
produce  a  speed  of  700  feet  of  paper  on  the  machine,  as  a  maximum. 
From  this  large  sheave,  multiple  ropes  (English  System)  will  deliver  the 
power  to  the  various  parts  of  the  machine  having  a  variable  speed,  and 
to  the  reel  counter. 

It  is  understood  also  that  the  Purchasers  will  furnish  an  independent 
variable  speed  electric  motor  for  driving  the  countershaft  in  the  base¬ 
ment,  of  the  slitter  and  winder,  as  before  mentioned,  and  also  they  will 
furnish  an  independent  electric  motor  for  driving  the  constant  speed  shaft 

and  equipment.  . 

For  each  of  the  seven  driven  parts  of  the  machine,  a  sheave  wheel, 
about  5  feet  o  inches  diameter  will  be  furnished  which  will  be  mounted 
on  a  shaft  carried  by  at  least  two  and  in  nearly  all  cases  three  ring 
oiling  babbitted  rigid  bearings  and  wedge  adjusting  stands,  in  the  base¬ 
ments.  To  this  shaft  a  cone  pulley,  about  54  inches  diameter  and  about 
30  inches  face  will  be  keyed  and  will  drive  upward  through  the  floor  of 
the  machine  room,  to  a  corresponding  cone  pulley  on  a  short  parallel 
shaft.  This  short  shaft  will  be  connected  to  a  second  short  shaft  by 
means  of  a  patented  cut-off  friction  clutch  (24  inch  triple  disc  on  the 
coiichers  and  calenders,  and  24  inch  double  disc  on  the  three  presses  ^rid 
two  dryer  nests).  To  the  latter  short  shaft  will  be  keyed  the  pinion  of 
a  pair  of  cast  steel  and  cast  iron  spur  gears  having  machine  cut,  helical, 
herringbone  teeth.  The  proportion  of  the  gears  will  be  about  i  to  4.  The 
large  spur  gear  will  be  keyed  to  the  intake  shaft  of  each  part  of  the 
machine.  The  two  short  shafts  and  the  intake  shaft  will  each  be  carried 
in  two  ring-oiling,  babbitted,  rigid  pillow  blocks,  mounted  on  a  heavy  box 
bedplate.  This  box  bedplate  will  have  attached  an  extension  which  will 
come  up  to  within  i  or  2  inches  of  the  intake  shaft  of  the  inboard  and 
so  that  a  block  of  wood  can  be  inserted  for  this  end  of  the  shaft  to  rest 
on  when  lug  clutch  is  thrown  out  and  the  roll  removed. 

The  position  of  the  belt  on  the  cones  is  to  be  controlled  by  a  suitable 
belt  shifter.  The  friction  clutch  cut  off  coupling  is  to  be  operated  from 
front  or  tending  side  of  machine.  ,  ,,  r  ^1, 

The  drive  of  the  reel  will  be  through  cones  and  pulleys  from  the 
sheave  jack  shaft  of  the  calender  drive  in  the  basement,  and  will  start 
and  stop  with  the  ropes. 

All  gears  to  have  proper  guards  where  they  turn  in. 

Foundation  Plates  and  Bolts. 

A  complete  set  of  cast  iron  foundation  plates,  12  inches,  14  inches, 
17  inches  and  18  inches  wide  from  standard  patterns,  extending  f*'0^ 
flow  box  to  winder  inclusive.  At  the  dry  part,  the^  plates  will  ha've  /4 
inches  wide,  i  inch  high,  upturned  flanges  on  both  sidp. 

All  joint  bolts  to  be  furnished  by  the  Builders,  but  all  foundation 
bolts  and  washers  are  not  included  in  these  specifications. 

In  addition  to  these  foundation  bolts  and  washers,  just  mentioned,  the 
foundation  bolts  and  washers  for  holding  the  drive  stands  and  bedplates 
are  not  included  in  these  specifications.  The  holding  down  tap  bolts  tor 


3/0 


MODERN  PULP  AND  PAPER  MAKING 


fastening  the  feet  of  the  machine  frames  to  the  foundation  plates  will  be 
furnished  by  the  Builders. 

Drawings. 

There  will  be  furnished  without  charge,  by  the  Builders,  the  necessary 
drawings  for  erection,  including  a  drawing  showing  a  plan  view  of  the 
foundation  walls  on  which  the  machine  may  rest  and  the  basement  shaft¬ 
ing  and  stands. 

Speed. 

_  Machine  designed  for  a  maximum  speed  of  700  feet  of  paper  per 
minute. 

In  General. 

The  object  of  these  specifications  is  to  set  forth  and  describe  as 
clearly  and  definitely  as  possible  all  parts  of  the  machine  and  its  equip¬ 
ment  that  are  to  be  furnished  by  the  Builders,  and  it  is  their  intention 
that  in  workmanship,  materials  and  finish,  this  machine  will  be  fully  equal 
to  others  of  its  class  that  they  have  built. 

Exceptions. 

The  Fourdrinier  wire,  apron,  deckle  straps,  jackets,  felts,  bolts,  etc., 
comprising  the  clothing  for  this  machine ;  also  the  steam,  water  and  stuff 
piping  to  and  frorn  the  machine,  not  otherwise  specified,  are  not  included 
in  these  specifications.  However,  a  full  set  of  cotton  drive  ropes  are 
included. 

Delivery. 

The  machine  to  be  painted  the  Builders’  standard  color,  and  to  be 
boxed  and  crated  suitable  for  railroad  shipment,  as  per  contract. 

Erection. 

The  Builders  further  agree  to  furnish  the  services  of  a  skillful  Erecting 
Engineer  whose  duty  it  shall  be  to  superintend  and  further  assist  in  the 
erection  of  the  before-mentioned  machine  upon  arrival  of  same  at  desti¬ 
nation.  The  board  and  lodging  of  the  said  Erecting  Engineer  shall 
devolve  upon  the  Purchasers,  but  his  wages  and  traveling  expenses  shall 
be  paid  by  the  Builders.  In  this  connection,  however,  it  is  further  under¬ 
stood- that  should  the  said  erection  be  delayed  beyond  the  term  of  say 
seven  weeks,  of  fifty-four  hours  each,  then  the  Purchaser  shall  pay  such 
additional  services  of  the  said  Erector. 

If  desired  by  the  Purchasers,  the  Builders  will  also  furnish  the  serv¬ 
ices  of  an  Assistant  Mechanic  whose  board  and  lodging,  traveling  ex¬ 
penses  and  wages  will  be  paid  by  the  Purchasers. 

The  Purchasers  are  to  furnish  all  necessary  laboring  help  and  mill¬ 
wright  help;  also  use  of  crane  and  other  handling  apparatus,  to  expedite 
the  erection. 


THE  MACHINE  ROOM 


371 


SPECIFICATIONS 

FOR  A 

156"  FOURDRINIER  PAPER  MACHINE 
FOR  MAKING  MANILA  WRAPPING  PAPER,  ETC. 

MADE  BY 

(Name  of  Builder  and  Address) 

FOR  THE 

(Name  of  Purchaser  and  Address) 

(Address  and  Date.) 

The  Design  material  and  labor  embodied  in  this  contract,  unless  other¬ 
wise  specified, ’is  to  be  the  best  of  the  several  kinds,  and  is  intended  to 
cover  the  general  detail  and  construction  of  one  Paper  Machine,  as 


hereinafter  specified  and  described,  subject  to  the  approval  of  . 

. Company,  hereafter  referred  to  as  the  Purchaser. 

. Company  (the  Builder)  shall 

allow  inspection  of  the  work  at  any  time  by  the  Purchaser,  or  his  Agent. 

In  cases  where  a  possible  doubt  exists  as  to  the  interpretation  of  these 
specifications,  the  Builder  shall  consult  with  the  Purchaser  before  taking 
steps  towards  the  performance  of  the  work. 

These  specifications  are  intended  to  embody  a  complete  machine  in 
all  its  parts,  as  called  for  by  the  contract;  but  any  changes  or  additions, 
or  extra  parts,  that  may  be  called  for,  shall  not  be  charged  as  Extras 
unless  the  same  shall  have  been  called  to  the  attention  of  the  Purchaser 
and  done  in  pursuance  of  a  written  order  from  the  Purchaser  or  his 

^Nothing  that  is  necessary  for  a  complete  installation  of  the  work 
herein  called  for  shall  be  construed  as  Extra. 

Guarantee.  1  u- 

The  Builder  herewith  guarantees  that  the  material  and  workmanship 
shall  be  the  best,  and  agree  to  replace  and  make  good  to  the  Purchaser, 
at  any  time  within  one  year  from  the  date  of  first  operation  of  the  ma¬ 
chinery,  any  portion  that  may  have  proved  to  be  defective,  under  ordi¬ 
nary  wear,  during  that  time.  ,  ,  ,,  i- 

Any  breakage  or  damage  to  the  machine,  caused  by  the  negligence  or 
incompetence  of  the  employees  of  the  Purchaser,  shall  not  be  included 
in  the  above  clause. 

Hand.  ,  r>  1  u 

When  standing  at  the  Breast  Roll  and  looking  toward  the  Reel,  the 
driving  arrangement  will  be  on  the  Right  Hand  side. 

Size  and  Wire. 

The  machine  will  be  made  for  Wire  156"  wide  and  seventy  feet  (70  ) 
long. 


372  MODERN  PULP  AND  PAPER.  MAKING 


Widths. 

Breast  Roll  . 158"  face 

Table  Rolls  . 158"  face 

Guide  and  Stretch  Rolls . 158"  face 

Dandy  Roll  . 158"  face 

Top  Couch  Roll  . 160"  face 

Bottom  Couch  Roll  . 158"  face 

Top  Press  Rolls  . 155"  face 

Bottom  Press  Rolls  . 154"  face 

Dryers  . 154"  face 

Calenders  . 152"  face 

Reels' . 156"  face 


Screens  and  Flow  Box. 

No  Screens  to  be  furnished  by  Builder.  Overflox  Box  made  from 
latest  designs  for  economy  of  space,  and  the  proper  distribution  of  pulp 
upon  the  apron,  with  adjustable  Overflow  Pocket  in  end  of  box,  and  6" 
galvanized  iron  pipe  connecting  same  with  Fan  Pump  Box,  so  as  to  pre¬ 
vent  the  flooding  of  the  Wire. 

Composition  Slide  Gate  and  Washout  Valves. 

Pumps. 

Eight  inch  (8")  improved  Iron  Turbine  Fan  Pump,  made  so  that  top 
half  of  the  pump  case  may  be  removed  without  interfering  with  the  shaft 
or  motor.  To  have  thrust  and  ring  oiling  bearings.  Fan  Pump  Box. 
No  other  Pumps  to  be  furnished. 

Wire  Guide. 

Nash  Patent  Wire  Guide. 

Breast  Roll. 

Of  Gun  Metal  thick,  18"  diameter,  138"  face ;  made  with  shaft 
running  entirely  through  the  roll,  with  cast  iron  spiders  pressed  on  the 
shaft  by  hydraulic  pressure,  and  keyed.  The  Gun  Metal  shell  to  be  ac¬ 
curately  bored  and  pressed  on  the  spiders  under  5000  lbs.  pressure  to 
the  square  inch. 

Journals  4"x8".  Gun  metal  adjustable  swivel  boxes.  Wood  Doctor 
for  Breast  Roll.  Composition  heads  for  ends  of  roll. 

Brass  Rolls. 

A  sufficient  number  of  brass  Table  Rolls  sVA  and  5"  diameter.  No.  10 
gauge,  138"  face,  to  fill  the  space  between  the  Breast  Roll  and  the  first 
Suction  Box;  journals  15/16"  diameter,  3J4"  long,  of  steel,  with  ad¬ 
justable  Gun  Metal  bearings,  with  end  thrust  attachment.  The  s/A  rolls 
to  fill  the  space  between  the  Breast  Roll  and  the  Slices. 

All  Needful  5"xi58",  No.  10  gauge;  and  io"xi58"  brass  Wire  Rolls, 
No.  6  gauge,  with  journals  2"  diameter  x  8"  long.  Gun  Metal  shells  in 
boxes  for  the  10"  rolls. 

The  Wire  Stretch  Roll  and  the  Guide  Roll  to  be  of  brass.  No.  6 
gauge,  10"  diameter  and  158"  face,  and  to  have  journals  projecting  beyond 
the  boxes  to  serve  as  handles  for  facilitating  the  handling  of  the  rolls. 

Wooden  Doctors  to  be  placed  on  two  of  the  lower  rolls  which  carry 
the  returning  Wire. 

All  rolls  to  be  made  of  seamless  drawn  brass  tubing,  accurately  bal¬ 
anced  and  ground  true  in  our  improved  grinder. 

Deckle  Arrangement. 

Deckle  Rods  and  Shafts  diameter,  made  of  iron  pipe  covered 

with  brass  tubing. 


THE  MACHINE  ROOM 


373 


One  extra  Deckle  Shaft  2i/4"  diameter,  with  two  flanged  pulleys  to 
support  straps.  Improved  brass  Shield  to  support  center  of  Deckle  Straps, 
with  Drain  Spounts  for  taking  off  the  water. 

Twenty-two  inch  composition  Deckle  Pulleys;  hubs  bore, 

long.  Brass  Deckle  Drums  20"  diameter  x  12"  face,  to  be  located  near 
the  Dandy  Roll  and  between  the  third  and  fourth  Suction  Boxes,  to  carry 
the  Deckles  at  that  point;  the  drums  to  revolve  with  a  brass  cased  Shaft 
resting  in  adjustable  brass  stands. 

Brass  Slices  made  extra  wide ;  one-half  of  Slice  to  have  hole  the 
other  half  to  have  slot.  Improved  Deckle  Poppets  made  extra  heavy. 
Deckle  Pulleys  made  for  2”x2j4^^  Deckle  Straps,  The  Deckle  Frames 
to  be  operated  from  the  front  side  of  the  machine. 

Suction  Boxes. 

Five  cast  composition  Suction  Boxes  with  wide  ribs,  or  flanges,  on 
same  to  prevent  their  springing  or  becoming  set,  and  made  with  handles 
on  each  end  so  that  they  may  be  readily  removed  from  the  machine. 
Boxes  to  be  hung  to  the  Fourdrinier  rails  with  bolts,  and  supported  with 
wood  girts  covered  with  brass  plates.  Also  adjusting  screws  for  same. 

Suction  Boxes  to  be  stationary.  Each  box  to  have  straightway^  valve 
connecting  with  4"  Suction  Pipe,  and  to  be  operated  from  front  side  of 
machine.  Perforated  Rock  Maple  Plates.  Deckle  Straps  to  cross 

three  of  the  Boxes.  A  system  of  brass  piping  for  priming  both  ends  of 
the  boxes  to  the  same  water  level,  so  that  the  machine  tender  need 
observe  the  tending  side  of  the  machine  only. 

Dandy. 

One  io"xi58"  plain  Dandy,  covered  with  No .  mesh  of  wire,  and 

to  be  equipped  with  an  internal  shower  pipe.  Composition  combination 
stick  stands,  having  vertical  adjustment.  Brass  Shower  Pipe  and  Wiper 
Bar.  The  Dandy  to  be  located  between  the  third  and  fourth  Suction 
Boxes.  Trolley  Arrangement  for  removing  the  Dandy  from  the  machine. 

Water  Pipes. 

Eight  inch  (8")  Water  Main  of  heavy  galvanized  iron  pipe;  large 
brass  supply  pipes  to  Breast  Roll;  Foam  Pipe;  Save-all  Fans;  Stretch 
Roll,  Suction  Boxes,  Pail  Fill;  and  Coucher  Shower,  with  improved  con¬ 
nections  and  straightway  valves.  The  unions  to  be  located  above  the 
valves. 

The  Shower  Pipes  at  Wire  Stretch  Roll  and  Hand  Guide  Wire  Roll 
to  have  Pistons.  The  Shower  Pipe  over  the  Breast  Roll  to  revolve. 

Brass  Water  Jet  for  cutting  the  sheet. 

Shake  Rails. 

The  Shake  and  Permanent  Rails  to  be  of  steel,  covered  with  cast 
brass,  8"  widex2i4"  thick.  The  Shake  Arm  to  come  close  to  the  floor 
so  as  not  to  interfere  with  the  putting  in  or  taking  out  of  the  Breast 
Roll,  and  to  be  driven  by  our  improved  Cone  Driving  Arrangement,  and 
Friction  Clutch. 

Posts  Under  Shake  Rails. 

2^"  diameter,  of  brass. 

Save-all  Pans. 

Five  inches  deep,  made  in  sections  with  spouts  for  each,  so  the  dif¬ 
ferent  sections  may  be  removed  between  the  posts.  Girts  for  the  above 
pans  to  be  made  of  channel  iron  C  wide,  trussed  and  covered  with 
Copper, 


374 


MODERN  PULP  AND  PAPER  MAKING 


Couchers. 

Both  rolls  to  be  covered  w.ith  Gun  Metal ;  top  roll  24"  diameter  x  160" 
face;  bottom  roll  28"  diameter  x  158"  face.  Journals  of  top  roll  to  be 
6"  diameter  X  10"  long;  journals  of  bottom  roll  to  be  7"  x  12". 

Both  the  rolls  to  be  made  with  a  shaft  running  entirely  through  the 
roll,  with  cast  iron  spiders  forced  onto  same  by  hydraulic  pressure  and 
keyed.  The  Gun  Metal  shell  to  be  accurately  bored  and  pressed  on  the 
spiders  under  5000  lbs.  pressure  to  the  square  inch. 

Bottom  roll  to  have  composition  water  ring  heads ;  no  composition 
heads  for  the  top  roll.  The  Coucher  Stands  and  Frames  *to  be  of  our 
latest  design  for  facilitating  the  putting  on  of  the  Wires  and  Jackets. 
The  Boxes  for  the  top  roll  to  be  on  the  under  side  of  swing  arms ;  the 
boxes  for  the  bottom  roll  to  be  water  jacketed.  Both  rolls  to  have  gun 
metal  lined  boxes.  Coucher  Board  to  be  trussed  with  an  8"  bowed  truss. 
Large  brass  Shower  Pipe.  Foot  Board  between  the  Couchers  and  first 
press  with  brass  Hand  Rail.  Compound  Levers  of  Iron,  Weights,  etc. 

Our  improved  Screw  Jack  Lifting  Arrangement  for  lifting  the  Top 
Roll,  greatly  facilitating  the  putting  on  of  the  Wires  and  Jackets. 

First  Press. 

Bottom  Roll  to  be  covered  with  Rubber,  thick,  24"  diameter,  154" 
face.  Top  Roll  made  of  Gun  Metal,  24"  diameter,  155"  face;  journals 
of  both  rolls  9"  diameter  x  12"  long. 

Felt  Arrangement  for  48  foot  felt.  Brass  Shower  Pipes,  etc. 

Cast  composition  Suction  Box  for  Felt,  with  perforated  Rock  Maple 
cover  i"  thick.  Felt  Stretcher  with  screws  of  Gun  Metal  i  11/13" 
diameter,  and  brass  cased.  The  Stretch  Roll  to  be  operated  by  large 
Hand  Wheel  and  Sprocket  Chain,  and  to  be  equipped  with  eccentric 
motion  for  operating  either  end  of  the  roll  separately. 

Gun  Metal  lined  water  jacketed  boxes,  and  our  improved  Screw  Jack 
Lifting  Arrangement,  for  lifting  one  or  both  rolls.  Swing  automatic 
Felt  Guide;  one  Hand  Guide.  Improved  Scoop  Doctor  with  brass  blade. 
Compound  Levers,  Weights,  etc. 

Second  and  Third  Presses. 

Same  as  the  First  Press.  The  Gun  Metal  shells  to  be  Ys"  thick  and 
forced  onto  the  iron  body  by  hydraulic  pressure. 

No  Suction  Box  for  second  or  third  Press  Felts.  No  Swing  auto¬ 
matic  Felt  Guides.  Otherwise  the  same  as  the  First  Press. 

Dryers. 

Forty  cast  iron  Dryers,  48"  diameter,  154"  face,  arranged  twenty  at 
the  bottom  and  twenty  on  top.  Journals  8"  diameter,  13"  long. 

One  Receiving  Dryer  about  24"  diameter,  154"  face;  journals  5”x9". 
Eight  Felt  Drygrs — two  for  each  Felt — 33"  diameter  x  154"  face;  journals 
sYL'yigYA  long. 

All  the  Dryers  to  be  fitted  with  .  Steam 

Joints  and  Improved  Scoops. 

All  Dryer  Boxes  fitted  with  Phosphor  Bronze  linings,  with  our  im¬ 
proved  Grease  Caps. 

The  Dryers  to  be  arranged  for  two  bottom  Felts  and  two  top  Felts, 
Each  Felt  to  have  one  Hand  Guide,  one  Automatic  Guide ;  one  Automatic 
Tension  Roll,  and  one  Horizontal  Felt  Stretcher. 

Dryers  to  have  the  Yoke  Drive. 

Walk  with  steps  and  Hand  Rail  at  the  back  side.  Improved  Gear 
Guard.  Stretcher  Screws  i  11/16"  diameter,  brass  cased.  The  Stretch 
Rolls  to  be  operated  by  large  Hand  Wheels  and  Sprocket  Chains,  and  to 
be  equipped  with  eccentrics  motion  for  operating  either  end  of  the  rolls 
separately.  Ring  oiling  boxes  for  all  Felt  and  Paper  Rolls  at  Dryers. 


THE  MACHINE  ROOM 


375 

The  Dryer  Gears  to  be  CUT  GEARb,  with  SPLIT  HUBS.  First 
bottom  and  last  top  Dryer  to  be  fitted  with  Improved  Doctors,  and  steel 
blades.  All  dryers  to  be  accurately  turned,  balanced  and  highly  polished 
on  the  face. 

Calenders. 

Three  stacks  of  chilled  iron  Calender  Rolls,  each  to  consist  of  nine 
rolls — ^one  28",  one  16",  six  14"  and  one  16"  all  152"  face. 

Housings  of  our  latest  design  for  removing  the  rolls  endwise.  Journals 
to  be  extra  long.  Composition  Friction  Rings  at  shoulders  of  journals. 
All  rolls  to  be  accurately  bored  and  Water  Jacketed  to  prevent  the  journals 
from  heating.  Dillon  Calender  Feed,  without  air  pipes  or  Blowers. 
Hydraulic  Lifting  Device  for  lifting  the  Calender  Rolls. 

Compound  levers,  Weights,  etc. 

Reels. 

One  set  of  our  latest  and  most  improved  Two  Upright  Reels,  18" 
diameter,  156"  face.  Reels  made  with  both  the  endwise  and  lateral 
adjustment,  and  driven  by  independent  belts,  with  tighteners. 

Friction  Wheels,  Straps,  etc.,  complete.  22"  Hand  Wheels. 

Slitting  and  Winding  Machine. 

To  be  of  any  standard  make  designated  by  purchaser. 

Felt  and  Paper  Rolls. 

All  Felt  Rolls  about  the  Presses  of  steel,  8l4”  diameter,  made  in  the 
latest  and  most  permanent  manner,  turned  and  covered  with  Brass 
Jackets,  with  improved  journals.  The  two  Paper  Rolls  in  front  of  the 
third  Press  to  be  of  brass;  lower  roll  7"  diameter;  upper  roll  7"  diameter 
and  made  light. 

The  Paper  Roll  over  third  Press  to  be  of  brass,  8"  diameter  and  driven 
by  power. 

All  Felt  Rolls  about  Dryers  of  steel,  8^4"  diameter,  turned  true  and 
smooth  on  the  face. 

All  Felt  and  Paper  Roll  Stands  about  Presses  to  be  Gun  Metal  lined. 
.\11  Felt  Roll  Stands  to  be  of  the  most  improved  adjustable  type,  with  six 
springs.  Gun  Metal  lined  Boxes. 

Two  214"  brass  rolls,  one  to  go  in  front  and  one  back  of  the  first 
Press,  to  be  used  as  Blow  Rolls. 


Frames. 

Of  our  heaviest,  latest  and  most  improved  designs. 

Shafting. 

Constant  and  variable  lines,  and  countershafts,  5  7/ 16",  4  7/ 16"  and 
3  diameter.  All  the  Shafting  to  be  milled  and  polished  and  fitted 

with  Flanged  Couplings. 

All  Collars  for  Shafting  to  be  of  cast  iron,  of  the  safety  type,  with 
two  set  screws  quartering  and  countersunk. 

Steam  Pipes. 

All  necessary  about  machine,  made  of  wrought  iron.  Ten  inch  steam 
main  and  six  inch  exhaust  main.  2"  and  i"  uprights. 


376 


MODERN  PULP  AND  PAPER  MAKING 


Pulleys. 


All  large  and  wide  on  the  face,  balanced  and  keyed  to  Shafting.  TIk 
Cone  Pulleys  to  be  keyed  to  Shafting  and  to  be  operated  by  patent  CU  i 

OFF  COUPLINGS.  ^  _ 

All  the  pulleys  on  both  the  constant  and  variable  lines  to  be  bxL-i i 


PULLEYS. 

The  Couchers,  Dryers,  and  Calenders  to  have  27  , 
Cut  Off  Couplings.  Set  Screws  over  aill  keyes. 


and  the  Presses  24" 


Driving  Arrangement. 


Machine  to  be  driven  by  any  required  system  of  drive,  detade  speci¬ 
fications  concerning  which  are  to  be  furnished  by  the  purchaser,  ihe 
Constant  and  Variable  lines  to  be  driven  by  engines,  or  motors,  furnished 

by  the  Purchaser.  ,  .  ..  ..  c  a 

The  Builder  is  to  furnish  one  driving  pulley  for  the  Constant  bpeed 
Line,  and  one  driving  pulley  for  the  Variable  Speed  Line. 

The  Main  Line  to  be  located  in  the  basement,  with  adjustable  ring 


oiling  boxes  for  same.  ^  ,  ,  -r, 

All  the  Shafting  Boxes,  Dryer  Boxes,  Coucher  and  Press  Roll  Boxes 
to  be  dowelled  after  the  machine  is  erected,  so  as  to  obviate  any  possibility 
of  their  being  moved. 


Foundation  Plates. 

Of  iron,  with  gutters  cast  on  the  side,  with  spouts  connecting  same 
with  the  space  between  the  machine  foundations.  Anchor  bolts  and 
washers  for  holding  the  foundation  plates.  The  floor  at  the  foundation 
plates,  at  the  back  side  of  the  machine,  to  be  level  with  the  top  of  the 
plates. 

Exceptions  to  a  Complete  Machine. 

Felts,  Belts,  Wires,  Deckle  Straps,  Jackets  and  Aprons. 

Speed  of  Machine. 

The  machine  to  be  guaranteed  strong  and  sufficiently  rigid  to  run 
successfully  at  a  speed  of  SSO  feet  per  minute. 


To  Be  Complete. 

Ready  to  ship  from  our  works,  by .  19...., 

contingent  upon  strikes,  fires,  accidents  and  other  causes  beyond  our 
control. 

Erection. 

The  Builder  is  to  furnish  the  time  of  one  competent  man  to  super¬ 
intend  the  erection  of  the  machine  in  the  mill  of  the  Purchaser. 

The  Purchaser  of  the  machine  is  to  pay  his  traveling  expenses  and 
board  and  to  supply  all  necessary  millwright  and  laboring  help. 

General  Conditions. 

All  feet  of  stands  to  be  planed,  and  all  other  parts  where  required. 
All  moving  parts  to  be  accurately  balanced.  The  machine  is  to  be  suitably 
painted.  The  machine  shall  be  built  along  lines  that  will  give  every 
possible  provision  for  the  safety  of  the  machine  tenders, 


THE  MACHINE  ROOM 


377 


Drawings. 

There  will  be  furnished  without  charge  by  the  Builder  a  drawing 
showing  a  plan  view  of  the  machine  and  its  driving  arrangement,  as 
hereinbefore  specified,  and  also  a  drawing  showing  a  plan  view  of  the 
foundation  on  which  the  machine  may  rest. 

Price  of  Machine. 

Terms  of  Delivery. 

F.  O.  B.  (Location  of  mfrs.  plant). 

Terms  of  Payment. 


Signed 


Signed 


XIV.  The  Finishing  Room. 


The  work  of  the  finishing  room  divides  itself  into  two  general 
classifications,  which  are  themselves  much  further  subdivided. 
The  two  classifications  are  (i)  making  rolls  of  paper  (2)  mak¬ 
ing  bundles  of  paper. 

Whether  bundles  or  rolls  are  to  be  made  depends  entirely  on 
the  purpose  for  which  the  paper  is  to  be  used. 

The  extent  of  the  operations  of  the  finishing  room  will  vary 
all  the  way  from  the  very  simple  state  of  affairs  in  a  newsprint 
mill  where  the  rolls  are  shipped  practically  as  they  come  from 
the  machine,  to  that  in  a  mill  making  a  wide  line  of  book  or 
writing  papers,  or  specialities  of  some  kind,  in  which  case  the 
finishing  room  may  well  be  one  of  the  most  extensive  and  im¬ 
portant  parts  of  the  whole  plant. 

Roll  Finishing. 

Rolls  of  Paper:  The  first  classification  is  the  simplest.  In 
most  cases  the  paper,  as  it  is  rewound  from  the  jumbo  roll 
formed  on  the  reels  in  the  machine  room,  passes  through  a  re¬ 
winder.  This  machine  usually  consists  of  a  rewinder  and  slitter 
combined  so  that,  by  means  of  various  cutting  devices,  the  opera¬ 
tors  are  able  to  obtain  whatever  sized  rolls  their  orders  may  call 
for. 

This  rewinding  and  cutting  operation  requires  the  severest 
attention.  A  dull  knife  will  often  result  in  spoiling  many  rolls 
of  paper.  The  knives  must  be  placed  at  exactly  the  right  points 
for  cutting  the  paper;  otherwise  oversized  or  undersized  rolls 
will  result.  Actually  the  slitting  process  and  the  rewinding 
process  are  not  distinct  and  separate  operations,  but  must  be 
considered  one  in  relation  to  the  other. 

The  rolls  must  be  wound  absolutely  straight  to  insure  a  uni¬ 
form  advancement  of  the  web  of  paper  from  the  jumbo  roll. 
The  sheet  of  paper  must  be  held  rigidly,  and  must  have  been 
properly  calendered  to  insure  presenting  a  good  uniform  surface 
from  tbe  jumbo  roll  to  the  finished  rolls,  otherwise  causing  rolls 
to  be  formed  that  have  hard  and  soft  spots.  A  roll  of  this  sort 
would  not  be  particularly  objectionable  if  it  were  to  be  used  as  a 
counter  roll,  but  if  it  were  going  to  be  further  cut  up  or  used  in 
a  bag  machine  or  any  other  automatic  machine  for  making  paper 
products,  serious  difficulties  would  follow.  For  instance,  the  roll 
could  not  be  properly  fed  to  the  machine.  The  slackness  of  one 

378 


THE  FINISHING  ROOM 


379 

side  would  cause  wrinkles,  followed  by  breaks.  This  would 
mean  an  immediate  rejection  of  such  a  roll  of  paper. 

There  are  hundreds  of  little  things  at  this  particular  stage  of 
paper  making — the  finishing  room — that  can  completely  offset 
the  value  of  a  good  sheet  of  paper.  Paper  that  has  had  all  the 
attention  and  care  that  paper  possibly  could  have,  before  being 
sent  to  the  finishing  room,  may  be  completely  ruined.  Conse¬ 
quently  extreme  precaution  must  be  exercised. 

The  machinery  should  be  of  the  best  and  most  improved 
makes  and  care  should  be  exercised  to  keep  it  in  the  best  order.'^ 
The  knives  of  the  slitters  must  be  kept  properly  sharpened  and 
not  allowed  to  sheer,  otherwise  feathery  edges  will  result,  or  an 
overlapping  will  take  place  between  the  consecutive  rolls.  This 
works  a  hardship  on  the  operators  who  are  taking  away  the 
paper  from  the  rewinder,  and  often  results  in  the  spoiling  of  a 
roll  due  to  the  inability  of  the  help  to  separate  it  from  another 
roll.  Spreaders  of  various  types  are  used  to  prevent  this,  the 
most  usual  type  of  spreaders  being  a  steel  strip  pressing  on  the 
paper  which  is  bowed  out  at  the  point  where  the  spreading  is 
required. 

Rewinding. 

There  are  various  methods  of  performing  this  operation  of 
cutting  and  rewinding.  One  of  these  is  the  surface  rewind 
method.  By  this  method  all  the  rolls  are  formed  side  by  side 
on  a  single  shaft  by  surface  contact  with  a  pair  of  revolving  sup¬ 
port  rolls,  on  which  the  rolls  of  paper  rest.  No  power  is  ap¬ 
plied  directly  to  the  rewind  shaft.  This  method,  when  the  equip¬ 
ment  is  properly  designed,  and  when  accompanied  by  the  proper 
method  of  slitting,  is  decidedly  superior  to  the  old  center  re¬ 
wind  method.  The  center  rewind  method  is  not  practical  when 
narrow  rolls  are  required,  as  they  will  not  stand  alone  after  they 
have  been  built  up  to  any  considerable  diameter.  Further  trou¬ 
ble  with  this  method  is  due  to  variation  in  the  thickness  of  the 
paper  across  the  width  of  the  sheet,  causing  the  rolls  to  build  up 
largest  where  the  web  is  thickest,  thereby  pulling  the  paper  faster 
on  the  thicker  portions,  thus  causing  the  web  to  feed  unevenly 
and  preventing  first  class  work. 

As  has  already  been  stated  it  is  generally  conceded  that  the 
surface  rewind  method  is  the  better  one,  and  the  next  point  to 
be  considered  is  what  is  the  best  method  of  slitting  so  that  the 
two  operations,  quite  distinct  from  each  other,  will  work  in  per¬ 
fect  unison  with  each  other. 

Slitting. 

The  rotary  shear,  or  rotary  slitter,  method  is  one  that  in  the 
past  has  been  widely  used  and  was,  at  one  time,  considered  to 
be  the  last  word  on  the  subject  of  slitting.  To  work  properly 
the  rotary  shears  must  have  a  keen  edge,  and  yet  this  edge  is 


38o  modern  pulp  AND  PAPER  MAKING  ; 

bound  to  become  dulled  slightly,  even  after  only  moderate  use, 
thereby  causing  a  ragged  or  frayed  edge  on  the  strips,  which 
then  become  interlaced  or  meshed  together  in  the  rewinding 
process.  As  before  stated,  when  this  interlacing  takes  place  it 
is  often  impossible  to  separate  the  rolls  from  each  other.  The 
slitter  shaft  should  be  heavy  enough  not  to  vibrate  or  chatter 
and  should  be  well  braced  and  the  knives  should  be  large  enough 
in  diameter  that  they  do  not  have  to  rotate  excessively  fast. 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  144. — Winder  and  rotary  slitter. 


On  account  of  serious  difficulties  in  maintaining  production 
and  high  class  finishing  with  the  rotary  slitters,  some  of  which 
have  been  touched  on  above,  the  score  cutter  has  come  to  be  much 
used  in  modern  finishing  rooms.  This  device  consists  of  a  sin¬ 
gle  cutting  disc  with  a  “V”  edge,  so  mounted  as  to  revolve  un¬ 
der  spring  pressure  against  the  surface  of  a  glass-hard  steel, 
cylinder.  This  surface  is  very  smooth  and  highly  polished.  The 
steel  cutter  wheel  is  mounted  on  ball-bearing  centers,  revolves 
practically  without  friction  and  has  an  actual  cleaving  action 
through  the  paper  at  the  point  of  contact  with  the  cylinder 
against  which  it  is  pressed.  This  appliance  invariably  yields  a 
clean  cut,  even,  perfect  sheet  or  roll  of  paper.  The  edge  of  the 


THE  FINISHING  ROOM  381 

paper  is  not  stretched,  owing  to  the  cleanness  of  the  cut.  Fur¬ 
ther,  there  is  not  the  same  difficulty  in  keeping  these  steel  cutter 
wheels  sharp  as  there  is  with  the  rotary  slitters,  since  they  do 
not  have  a  regular  knife  edge  but  rather  a  very  hard  permanent 
edge,  something  like  a  cold  chisel.  The  variety  of  materials  that 
can  be  handled  with  such  equipment  is  very  great — all  the  way 
from  the  most  delicate  tissues  to  coarse  boards,  also  fabrics,  tex¬ 
tiles,  etc.  Great  difficulty  was  experienced  with  rotary  slitters 


at  very  high  speeds,  but  the  score  cutter  apparently  knows  no 
limit  as  to  speed. 

No  matter  what  principle  has  been  embodied  in  reducing  the 
jumbo  roll  to  the  sizes  specified  in  the  orders,  whether  to  9-inch 
rolls  or  40-inch  rolls  or  what  not,  one  can  hardly  place  too  much 
emphasis  on  the  necessity  of  taking  every  precaution  to  prevent 
bad  edges,  slitter  breaks,  slack  edges  and  to  insure  exact  and 
proper  width  of  roll. 

Another  precaution  that  must  be  taken  is  the  prompt  inser¬ 
tion  of  plugs  in  the  rolls,  so  that  when  these  are  later  piled  up 
in  transportation  or  storage  they  will  not  be  pressed  inward  and 
flattened  and  loose  their  symmetrical  cylindrical  shape. 

After  the  rolls  have  been  cut  to  the  proper  size,  plugs  in- 
^serted,  etc.,  they  are  ready  for  the  final  stages  of  finishing.  This 


Courtesy:  Cameron  Machine  Co.,  Brooklyn,  N.  Y. 

Fig.  145. — Score  cutter  type  of  winder  and  slitter. 


3^2  Modern  pulp  and  paper  making 

consists  in  putting  on  the  wrapper,  which  may  be  done  either  by 
hand  or  mechanically,  In  large,  modern  finishing  plants  me¬ 
chanical  methods  are  usual  on  account  of  the  high  cost  and  un¬ 
certainty  of  labor.  The  roll  is  wrapped  with  either  one.  two  or 
three  plies  of  good  durable  paper.  A  strong  sheet  of  6o-pound 
Kraft  is  suitable  for  this  purpose.  This  is  to  insure  against 
rough  usage  and  tumbling  during  transportation. 

The  width  of  the  wrapper  is,  of  course,  determined  by  the 
width  of  the  roll;  sufficient  allowance  being  made  to  have  the 
ends  of  the  wrapper  almost  meet  when  folded  over  on  the  ends 
of  the  roll.  An  inside  header  should  be  placed  under  this  folded 
portion  to  prevent  any  paste  reaching  the  outer  edges  of  the  roll. 
The  outside  header  is  then  pasted  over  the  ends  of  the  roll, 
serving  not  only  as  a  means  of  securing  the  end.  but  adding  to 
the  neatness  of  the  roll  when  properly  applied.  The  work  is 
now  completed  with  the  exception  of  stenciling  and  labeling. 
Care  should  be  taken  that  this  work  is  done  neatly  and  not  in 
haphazard  fashion,  otherwise  when  a  number  of  rolls  are  stored 
in  a  jobber’s  warehouse  the  appearance  of  good  workmanship 
is  lost.  With  a  material  like  paper,  appearance,  even  in  minor 
details,  counts  for  a  great  deal. 

Bundle  Finishing. 

Returning  to  the  other  phase  of  finishing — bundle  finishing — 
it  is  well  to  note  at  the  outset  that,  although  this  operation  is  not 
so  difficult  as  roll  finishing,  it  is  more  tedious  and  requires  more 
operators. 

Large  jumbo  rolls  averaging  29  inches  in  diameter  are  brought 
from  the  machine  room  and  placed  on  an  unwinder,  from 
which  they  are  fed  to  the  cutters,  where  they  are  cut  into 
the  desired  widths  and  also  cut  off  transversely  at. regular  inter¬ 
vals,  thus  making  rectangular  sheets  of  regular  and  exact  size. 
The  sheets  are  gathered  up,  counted  and  placed  in  piles.  In 
some  mills  this  is  still  done  by  hand,  but  the  majority  of  finish¬ 
ing  rooms  now  use  machines  called  “lay  boys”  for  this  purpose. 

The  smaller  sizes  of  sheets  are  shipped  flat.  These  are 
wrapped  and  tied,  the  nature  of  the  wrapper  varying  with  the 
size  of  the  bundle.  The  bundles  are,  as  far  as  possible,  arranged 
at  a  weight  of  100  pounds.  The  wrapper  in  such  a  case  should 
be  of  three  sheets  of  paper  of  6o-pound  basis.  This  operation 
naturally  varies  with  the  nature  of  the  paper  and  the  degree  of 
caution  taken  by  the  maker.  Also  there  is  a  difference  accord¬ 
ing  to  whether  the  paper  is  for  domestic  or  export  trade.  Bun¬ 
dles  for  export  trade  are  sometimes  enclosed  in  heavy  cases  of 
wood  or  fibre  board. 

Frequently  orders  are  taken  calling  for  large  size  sheets 
which  cannot  conveniently  be  shipped  flat.  These  are  folded. 
The  folding  is  done  in  two  ways,  depending  on  the  customer’s 
preference.  One  way  is  simply  to  fold  the  sheet,  permitting  the 


THE  FINISHING  ROOM  383 

pressure  of  the  bundle  to  crease  it  rather  sharply.  The  other 
method  of  folding  is  the  interlapping  method  in  which  the  sheets 
are  interlapped  by  the  ream  so  as  to  prevent  creasing  when  com¬ 
pressed  by  the  weight  of  the  bundle.  Of  the  latter  method 
there  are  again  two  subdivisions,  the  loose  and  the  hard,  de¬ 
pending  on  the  customer’s  preference. 

Efficient  handling  of  cut  paper  is  necessary  m  order  to  main¬ 
tain  production  and  orders  should  be  so  arranged  that  there  will 
not  be  too  much  waste  as  a  result  of  the  trim. 


Fig.  146.— Typical  finishing  room  equipped  for  sorting,  counting  and 

bundling  fine  paper  by  hand. 


Sheet  Cutters  and  Cutter  Tables  or  Lay  Boys:  There  are 
many  various  types  of  sheet  cutters.  It  is  necessary  to  select  a 
make  best  suited  to  the  needs  of  the  particular  kind  of  paper  to 

be  cut.  .  , 

The  function  of  sheet  cutters  is  to  cut  paper  from  jumbo 
rolls  into  sheets  of  specified  lengths  and  widths.  Some  of  these 
cutters  are  equipped  with  two  fly  knives  making  it  possible  to 
cut  two  different  lengths  of  sheet  at  one  operation. 

The  widths  of  the  sheets  are  determined  by  the  slitters.  The 
paper  is  first  slit  into  desired  widths  before  passing  to  the  fly 
knives.  Slitters  are  mounted  on  revolving  shafts  located  on  the 
cutter  frame,  but  back  of  the  revolving  or  fly  knives,  so  that 
when  the  sheets  pass  through  the  slitters  they  are  already  cut  to 


384  MODERN  PULP  AND  PAPER  MAKING 

the  desired  widths.  In  cutting  some  grades  of  p^aper  such  as 
market  paper,  the  cutters  may  be  furnished  with  either  8  or  12 
jumbo  rolls  and  the  paper  is  counted  as  it  is  cut.  With  8  rolls 
3  cuts  make  one  quire;  with  12  rolls  2  cuts  one  quire,  a  quire 
being  24  sheets. 

In  cutting  fine  papers  it  makes  no  difference  as  to  the  number 
of  rolls  cut  at  the  same  time,  as  this  grade  of  paper  cannot  be 
counted  as  cut  on  account  of  the  very  careful  sorting  required; 
in  the  case  of  market  papers,  etc.,  the  paper  can  usually  be 
counted  and  sorted  satisfactorily  in  one  operation.  The  above 
applies  only  to  the  ordinary  cutting  table  and  cutter  girls  for 
laying,  sorting,  counting  and  jogging  into  reams  or  quires. 


Courtesy:  Moore  &  White  Co.,  Philadelphia,  Pa. 

Fig.  147. — Lay-boy  as  used  in  connection  with  cutter  in  finishing  room. 

The  lay  boy  is  an  automatic  machine  which  is  attached  to 
the  front  side  of  the  cutter,  which  receives  the  sheets  as  they  are 
delivered  from  the  fly  knives  and  places  them  on  the  jogging 
table  automatically.  The  capacity  of  these  lay  boys  is  far  greater 
than  the  hand  operation,  especially  on  fine  papers  as  the  paper  is 
heavy  and  lies  flat  without  curling. 

Super-Calendering. 

Super-Calenders:  The  Super-Calenders  are  machines  used 
for  giving  a  smooth  surface  or  glazing  to  papers  requiring  more 
finish  than  can  be  given  on  the  calenders  at  the  end  of  the  paper 
machine. 

A  stack  of  these  super-calenders  usually  contains  either  nine 
or  eleven  rolls.  One  roll  is  of  chilled  polished  steel  and  the  next 
roll  of  cotton  or  paper.  These  rolls  are  placed  alternately  in 
the  stack  beginning  at  the  bottom  with  a  steel  roll — first  steel 
and  then  cotton  or  paper.  The  reason  that  these  stacks  of  calen¬ 
ders  contain  an  odd  number  of  rolls,  such  as  7,  9  or  ii  rolls,  is 
so  that  the  paper  may  go  over  the  top  of  the  first  roll  and  pass 


THE  FINISHING  ROOM  385 

down  through  each  nip  of  the  calenders,  and  come  through  the 
last  or  bottom  nip  on  the  working  side  of  the  stack. 

The  cotton  or  paper  rolls  are  made  by  pressing  discs  of  the 
material  onto  an  iron  or  steel  core  by  dydraulic  pressure  and 
then  they  are  turned,  ground  and  polished  on  the  surface. 

These  paper  or  cotton  rolls  thus  prepared  and  finished  make 
a  beautiful  surface  when  placed  alternately  in  the  stack.  The 
steel  rolls  having  a  hard  polished  surface  and  the  cotton  or  paper 


Courtesy:  The  Pusey  and  Jones  Co.,  Wilmington,  Del. 

Fig.  148. — Super-calender. 

rolls  also  being  polished,  but  of  a  more  yielding  nature,  have  an 
effect  on  the  surface  of  the  sheet  of  paper  resembling  the  ironing 
of  a  shirt  bosom.  To  add  to  this  ironing  effect  the  stack  of 
calenders  must  be  run  for  a  time  without  the  sheet  on  them  and 
until  they  became  quite  hot,  due  to  friction.  This  finishing  ef¬ 
fect  is  also  augmented  by  applying  steam  showers  to  the  surface 
of  the  paper  just  as  it  enters  the  top  of  the  stack  in  the  first 
nip.  In  some  cases,  steam  showers  are  applied  to  both  sides 
of  the  sheet,  but  the  most  common  procedure  is  to_  apply  to  one 
side  at  a  time  and  turning  the  sheet  over  every  time,  it  is  run 
through  the  stack.  This  is  done  to  insure  an  even  finish  on  both 
sides  of  the  paper  and  also  to  prevent  the  sheet  from  curling ;  all 


386  MODERN  PULP  AND  PAPER  MAKING 


papers  treated  in  this  manner  are  called  super-calendered.  These 
super-calenders  are  run  at  a  speed  of  approximately  i,ooo  feet 
per  minute. 

An  immense  variety  of  finishing  room  machinery  has  been 
developed,  all  of  which  it  would  be  impossible  to  describe  in 
such  a  work  as  this.  However,  all  of  these  machines  follow  the 
main  types  we  have  described  and  vary  only  in  the  introduction 
of  special  devices  intended  to  increase  production,  improve  quality 
and  facilitate  and  lighten  the  work  of  the  operators. 


Courtesy :  Holyoke  Machine  Co.,  Holyoke,  Mass. 


Fig.  148a. — Motor  driven  super-calender  stack. 

Storage  and  Shipment. 

The  efficiency  of  a  modern  finishing  room  depends  largely 
on  the  equipment  installed  for  handling  the  rolls  and  bundles  of 
paper.  Of  recent  years  much  has  been  done  in  this  connection 
by  introducing  traveling  cranes  and  overhead  conveying  systems 
for  bringing  the  jumbo  rolls  into  the  finishing  room  from  the 
machine  room  and  for  storing  the  finished  rolls  and  bundles. 
Tiering  machines  have  also  proved  exceedingly  useful.  These 
are  small  trucks  with  an  elevator  device.  The  roll  of  paper  is 
rolled  onto  the  truck  when  the  platform  is  at  ground  level,  then 
the  platform  is  elevated  and  the  roll  pushed  off  into  its  place  in 
the  warehouse  or  car.  These  devices  will  handle  considerable 
weights,  lift  to  any  reasonable  height  and  can  be  operated  with 
facility  by  one  man. 

The  less  the  paper  is  handled  by  manual  labor  the  better,  be- 


THE  FINISHING  ROOM  387 

cause  while  a  roll  of  paper  is  not  exactly  fragile,  it  is  compara¬ 
tively  easy  to  damage.  If  a  corner  of  a  roll  of  paper  is  damaged 
the  roll  must  be  unwrapped  and  stripped  until  the  entire  damaged 
portion  is  removed. 

It  is  always  preferable  to  store  roll  paper  standing  on  end 
because  this  preserves  the  cylindrical  shape  of  the  roll.  Also  in 
the  majority  of  cases  it  utilizes  the  storage  space  to  the  best  ad¬ 
vantage.  Even  a  short  period  in  storage  or  transportation  lying 
on  its  side  will  subject  a  roll  to  enough  pressure  that  it  will  not 
remain  perfectly  cylindrical.  This  gives  rise  to  a  great  deal  of 
trouble  on  modern  printing  presses  as  the  paper  unrolls  in  an 
irregular  manner,  and  even  the  most  imperceptible  alterations 
in  tension  give  much  trouble  on  these  delicate  high  speed  ma¬ 
chines. 

Special  trucks  have  been  devised  for  handling  paper,  the  nose 
of  which  is  flat  and  thin,  consisting  of  a  single  piece  of  steel. 
This  is  easily  inserted  under  the  edge  of  the  roll,  as  it  stands  on 
end  on  the  floor,  and  when  the  roll  is  tipped  back  it  reclines  in  a 
cylindrical  steel  plate  depression,  in  which  position  it  cannot 

possibly  be  injured.  ^ 

Care  should  be  taken  not  to  leave  rolls  standmg_  where  they 
will  be  in  the  way  of  trucks,  etc.  Much  good  paper  is  needlessly 
damaged  by  attempting  to  utilize  passages  in  warehouse,  etc., 

for  storage. 

Cars  in  which  paper  is  to  be  shipped  should  be  caretully  ex¬ 
amined  for  nails,  bolts,  etc.  The  floor  of  the  car  should  be 
covered  with  strong  paper  before  any  rolls  are  loaded.  It  is  a 
good  plan  to  nail  a  strip  of  clean  wood  around  the  car  about 
four  feet  from  the  floor.  If  the  car  is  only  partly  loaded  the 
rolls  should  be  specially  well  braced  with  strong  timbers  and 
care  should  be  taken  that  the  ends  of  these  timbers  do  not  come 
in  direct  contact  with  any  of  the  rolls.  Although  under^  present 
circumstances  cars  are  frequently  loaded  double-deck  it  is  better 
as  a  general  rule  only  to  have  one  tier.  It  is  a  good  rule  to 
sume  that  whatever  the  rated  capacity  of  the  car  rnay  be,  if  the 
entire  floor  is  tightly  packed  with  rolls  of  paper,  it  is  carrying 
a  sufficient  load.  However,"  at  present,  two  tiers  are  frequently 
necessary,  and  that  being  the  case,  even  more  care  should  be  exer¬ 
cised  with  the  top  tier  than  the  bottom  one,  as  it  will  be  more 
affected  by  the  motion  of  the  train.  Before  closing  the  car 
heavy  timbers  should  be  placed  across  the  doors. 


XV.  General  Design  of  Pulp  and  Paper  Plants. 


It  is  not  possible  to  give  in  a  single  chapter,  or  even  a  single 
book,  such  information  as  would  enable  a  previously  inexperi¬ 
enced  person  to  undertake  the  complete  design  of  a  plant  for 
making  any  kind  of  pulp  or  paper. 

If  that  were  possible,  there  would  be  small  need  for  the 
services  of  engineers  who  have  made  the  design  of  plants  for 
this  purpose  a  life  study.  The  final  efficiency  (or  inefficiency) 
of  a  big  pulp  and  paper  mill  will  depend  on  how  a  multitude  of 
minor  problems  have  been  settled,  and  the  highest  qualities  of 
engineering  experience  and  good  judgment  alone  suffice  to  meet 
these  requirements. 

Anyone  contemplating  investing  money  in  a  plant  for  manu¬ 
facturing  any  kind  of  pulp  or  paper  should  retain  the  services 
of  a  competent  engineer,  preferably  one  known  to  have  had 
previous  experience  in  such  matters,  and  then  his  decisions 
should  be  abided  by. 

However,  there  are  a  considerable  number  of  items  that 
anyone  taking  an  active  part  in  the  manufacture  of  pulp  and 
paper  should  know  about,  that  do  not  exactly  fit  into  any  of 
the  other  chapters  of  this  book,  and  so  are  being  considered  un¬ 
der  the  present  heading. 

Such  are  problems  of  location,  water  supply,  railroad  facili¬ 
ties,  fire  protection,  illumination,  ventilation,  piping,  power  trans¬ 
mission,  etc.  Each  of  these  subjects  might  well  be  the  subject 
of  a  separate  treatise.  Excellent  works  have  been  written  on 
many  of  them.  Consequently,  they  will  only  be  discussed  briefly 
in  the  present  connection,  with  special  reference  to  the  actual 
manufacture  of  pulp  and  paper. 

Location. 

Three  chief  factors  influence  the  location  of  a  pulp  and  paper 
plant:  supply  of  raw  material,  power  and  disposal  of  finished 
product.  If  a  plant  could  be  located  at  a  point  favorable  both 
to  the  obtaining  of  raw  material  and  the  market  for  the  fin¬ 
ished  paper  it  would  be  ideal.  This  is  now  rarely  possible.  The 
modern  tendency  is  to  locate  the  plant  where  the  raw  material  is. 
Immense  pulp  and  paper  mills  are  being  operated  in  the  most 
remote  parts  of  Canada,  far  from  any  market  for  their  products. 
In  common  with  all  other  manufacturing  processes,  if  anything 
has  to  be  shipped  a  long  distance,  it  is  better  to  ship  a  compara¬ 
tively  small  bulk  of  material  which  has  been  enhanced  in  value 

388 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  389 

by  manufacture  than  a  larger  bulk  of  material  yet  to  be  en¬ 
hanced  in  value.  The  latter  proposition  involves  paying  freight 
on  a  lot  of  substance  that  is  subsequently  got  rid  of  in  manu¬ 
facture. 

Many  paper  mills,  especially  those  making  the  finer  grades  of 
paper  and  specialties,  are  located  far  from  any  source  of  raw 
material.  This  is  largely  due  to  circumstances  connected  with 
power  and  labor.  Years  ago  groups  of  mills  grew  up  at  certain 
points  because  at  that  time  they  were  advantageously^  situated 
with  regard  to  power  and  raw  material.  The  communities  that 
have  grown  up  around  these  mills  are  largely  populated  with 
men  familiar  with  the  industry.  It  is  easier  to  get  the  highest 
class  of  labor  in  such  a  location.  Moreover,  the  power  is  still 
there  and  consequently  the  mills  remain  there. 

Other  factors  that  influence  the  location  problem  are  near¬ 
ness  to  supplies  of  equipment  and  chemicals,  climate,  water,  tax¬ 
ation,  personal  preferences  of  important  officials,  sentimental 
considerations,  etc. 

The  above  remarks  deal  merely  with  the  general  location,  i.  e., 
why  mills  are  numerous  in  some  parts  of  the  country  and  scarce 
in  others.  We  will  now  consider  the  details  regarding  a  suita¬ 
ble  pulp  or  paper  mill  site. 

If  we  consider  first  a  development  consisting  of  a  sulphite 
mill,  ground  wood  mill  and  paper  mill,  where  the  wood  is  re¬ 
ceived  by  rail,  it  is  obvious  that  such  an  industry  should  prefer¬ 
ably  be  situated  on  the  banks  of  some  large  body  of  water.  When 
we  come  to  discuss  water  supply  later  in  this  chapter  we  will 
deal  with  the  reasons  for  this,  but  assuming  that  several  million 
gallons  of  water  are  required  per  day,  the  advantages  of  such 
a  location  are  immediately  apparent.  Failing  this,  artesian  wells 
must  be  sunk  at  great  expense.  Some  of  the  paper  mills  in  the 
Kalamazoo  district  have  had  to  do  this,  owing  to  the  gradually 
increasing  inadequacy  of  the  water  supply,  which  was  originally 
quite  sufficient. 

Now,  the  banks  of  rivers  are  very  various  in  formation, 
and  putting  the  plant  near  the  river  will  sometimes  increase  the 
engineering  work  necessary  to  provide  suitable  foundations  and 
room  for  buildings.  It  is  ideal  when  a  level  location  can  be 
secured  right  beside  a  good  sized  river  or  lake.  However,  in 
many  cases,  on  account  of  the  desire  to  utilize  water  power,  pulp 
and  paper  mills  are  located  at  points  where  the  site  has  literally 
to  be  carved  out  of  the  banks  of  the  river. 

The  most  natural  arrangement  of  the  parts  of  such  a  plant 
is  to  have  the  sawmill,  wood  room,  digester  house,  sulphite 
mill,  beater  room,  machine  room  and  finishing  room  follow  right 
one  after  the  other  in  the  order  named,  material  thus  progress¬ 
ing  through  the  plant  in  a  straight  line.  Frequently,  however,  to 
secure  economy  of  space  and  to  surmount  natural  obstacles,  some 
parts  of  the  plant  have  to  be  in  basements  below  others.  The 


390  MODERN  PULP  AND  PAPER  MAKING 

less  of  this  that  is  done,  the  simpler  will  be  the  conveyor  and 
elevator  systems  required,  the  less  will  be  the  power  used  up  in 
elevating  materials  and  the  arrangement  of  the  piping  for  steam, 
water,  stock,  etc.,  will  be  just  that  much  easier.  .Provided  the 
conditions  (viz.,  coal  storage,  ash  handling,  etc.,  will  permit)  it 
is  always  preferable  to  place  the  boiler  house  centrally,  or  so  that 
steam  lines  supplying  paper  mill  and  sulphite  mill  will  be  reduced 
to  a  minimum. 

Room  must  be  provided  for  storage  of  wood.  This  subject 
has  already  been  discussed  at  some  length  in  the  chapter  on  the 
wood  room.  Due  precaution  should  be  exercised  that  the  area 
chosen  for  wood  storage  is  not  liable  to  be  flooded  and  is  not  a 
fire  menace  to  the  plant  or  to  other  adjoining  properties. 

Railroad  Facilities. 

In  laying  out  the  plant  regard  should  be  given  to  the  location 
of  sidings,  which  should  be  of  adequate  capacity.  Also,  if  there 
are  several  railroads  touching  the  point,  the  sidings  should  be  ar¬ 
ranged  so  as  to  have  the  most  convenient  connections  with  all  of 
them.  Sometimes  the  plant  is  located  on  a  slope  with  one  rail¬ 
road  on  the  high  level  back  of  the  plant  and  another  along  the 
water-front.  In  such  a  case  it  is  very  convenient  to  arrange  to 
receive  raw  materials  over  the  road  on  the  high  level  and  to  ship 
finished  products  out  on  the  low  level.  Frequently  it  will  pay 
the  mill  well  to  own  a  locomotive  for  switching  purposes,  thus 
being  more  or  less  independent  of  the  service  rendered  by  the 
railway  company.  Apart  from  steam  locomotives,  small  gasoline 
locomotives  are  used  for  this  purpose,  which  are  specially  use¬ 
ful  as  all  fire  risk  is  removed.  Excellent  electric  locomotives  are 
also  obtainable,  operating  either  from  a  trolley,  a  third  rail  or 
with  storage  batteries.  Car-hauls,  which  are  hoists  arranged  for 
pulling  cars  short  distances  around  a  plant,  will  be  found  very 
useful  when  a  locomotive  is  not  at  the  disposal  of  the  plant. 
If  a  crane  is  at  hand  for  loading  or  unloading  coal  or  wood  it 
can  be  used  as  a  car  shifter.  In  laying  out  sidings  ordinary  good 
judgment  must  be  exercised  so  that  cars  which  are  being  loaded 
or  unloaded  will  not  be  in  the  way  of  other  operations. 

Piping. 

For  water  supply  and  fire  protection,  cast-iron  pipe  is  usually 
used.  This  variety  of  pipe  lasts  very  well  when  buried  in  the 
ground,  and  is  generally  satisfactory  when  used  in  i2-foot  lengths, 
with  caulked  joints  of  the  bell  and  spigot  type.  Wrought  iron 
or  steel  pipe  can  be,  and  often  is,  used  for  this  service,  but  its 
use  is  not  desirable  as  it  cannot  be  depended  on  as  can  cast-iron 
pipe.  Not  only  will  it  seldom  last  so  long,  but  it  may  corrode 
and  give  out  unexpectedly  soon.  This  is  a  drawback  inseparable 
from  the  nature  of  the  material.  Galvanizing  has  some  preserv- 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  391 

ative  effect,  but  not  much  in  actual  practice.  Wrought  iron,  how¬ 
ever,  is  much  superior  to  steel  pipe. 

Cast-iron  pipe  can  also  be  used  for  many  other  purposes 
around  the  pulp  and  paper  mill.  This  material  can  now  be  ob¬ 
tained  in  almost  any  diameter  from  2  inches  up,  and  in  any 
length  required.  Flange  joints  can  be  had,  as  well  as  bell  and 
spigot  joints,  and  all  kinds  of  fittings.  _  Such  small _  cast-iron 
pipe  is  excellent  for  handling  bleach  liquor.^  ^  Cast-iron  pipe 
is  also  used  for  handling  stock  from  the  blow-pit  to  the  scieens 

in  the  sulphite  mill,  etc.  ,  •  1  u 

For  ordinary  connections  for  water  and  stock  in  the  beatei 
room  and  machine  room  where  Kraft  and  ground  wood  (neutral 
or  alkaline)  stock  predominates,  wrought  iron  pipe  is  satisfac¬ 
tory.  If  sulphite  predominates  galvanized,  flanged  cast-iron  pipe 
is  preferable  because  most  satisfactory  in  the  long  run,  although 
first  cost  is  higher.  Wrought  iron  pipe  has  higher  tensile 
strength  than  cast-iron  pipe  of  the  same  size  and  is  less  liable 
to  be  damaged  by  strain,  blows,  etc. 

In  the  acid  plant,  and  for  acid  lines  in  the  digester  house, 
hard  lead  pipe  or  lead-lined  iron  pipe  is  used.  Hard  lead  is  lead 
which  contains  a  small  percentage  of  antimony.  It  resists  aF 
most  all  acids.  Unless  made  with  special  skill,  lead  lined  pipe 
will  give  trouble  through  the  lead  lining  separating  from  the 
pipe.  There  is  at  least  one  line  of  lead-lined  pipe  on  the  mar¬ 
ket  which  has  been  developed  to  such  a  point  that  no  trouble  of 
this  kind  is  experienced.  All  kinds  of  fittings  and  valves  can 

also  be  secured  in  this  material. 

Bronze  piping  is  used  for  some  of  the  smaller  connections 
where  acid  containing  liquids  are  being  handled.  It  has  not  the 
resistance  to  acid  of  the  lead,  but  it  is  easier  handled  m  small 
sizes  and  has  greater  mechanical  strength. 

All  pipe  lines  carrying  steam  or  hot  liquids  should  be  well 
insulated  with  magnesia  or  some  other  good  insulating  material. 
The  manufacturers  of  these  materials  have  compiled  tables 
(which  can  be  obtained  froin  any  of  them)  which  will  enable 
exactly  the  right  thickness  of  insulation  to  be  estimated. 

Steam  piping  should  be  wrought  iron  or  steel.  Manufac¬ 
turers  of  this  material  make  three  grades :  “Standard,  Extra 
Heavy,”  and  “Double  Extra.”  For  pressures  up  to  160  pounds 
all  pipe  over  14  inches  should  be  ^-inch  O.  D.  pipe.  All  other 
pipe  should  be  standard  full  weight,  except  high-pressure  feed 
and  blowoff  lines,  which  should  be  extra  heavy.  For  pressures 
from  160  to  200  pounds,  and  with  superheated  steam,_  all  high 
pressure  feed  and  blow-off  lines,  high  pressure  steam  lines  with 
threaded  flanges,  etc.,  should  be  extra  heavy.  Pipe  14  inches 
and  over  should  be  ^-inch  O.  D.  pipe.  Full  weight  pipe  should 
be  used  for  all  steam  lines  other  than  those  mentioned  above  on 

1  See  “How  We  Solved  Bleach  Pipe  Problem,”  W.  H.  Scott.  Paper  Industry, 
Nov.,  1919.  pg-  623* 


392  MODERN  PULP  AND  PAPER  MAKING 

which  pressures  between  150  and  200  pounds  are  maintained. 
Flanges  should  be  cast  iron,  threaded,  except  for  superheated 
steam,  when  solid  rolled  steel  flanges  should  be  used.  Welded 
flanges  are  used  on  many  lines  with  satisfactory  results. 

Steam  piping  is  best  carried  out  by  a  reliable  piping  contrac¬ 
tor,  whose  experience  will  tell  him  just  what  weight  and  variety 
of  pipe,  flange,  fitting  and  methods  of  support  to  use  in  any 
given  case.  Moreover,  such  people  have  devised  many  special 
joints  and  fittings.  However,  the  above  brief  notes  may  be  con¬ 
sidered  good  practice  as  far  as  they  go. 

In  designing  systems  of  steam  piping,  when  the  proper  size 
and  weight  of  pipe  has  been  determined,  the  next  item  to  consider 
is  the  removal  of  the  water  of  condensation  that  is  always  present, 
but  wbich  can  be  much  reduced  by  efficient  heat  insulation.  The 
effect  of  water  moving  through  a  pipe  at  a  high  velocity  is  much 
the  same  as  that  of  a  solid  body  when  it  comes  in  contact  with 
elbows,  valves,  etc.  Even  if  there  is  no  actual  destruction  of 
pipe  or  fittings  from  this  hammer  effect,  there  will  be  a  constant 
bammering  and  abnormal  vibration  which  will  in  time  loosen  the 
joints  and.  cause  leaks. 

The  system  should  be  so  arranged  that  there  are  no  places 
where  water  will  be  pocketed  and  carried  along  by  the  steam  in 
slugs.  This  is  particularly  important  with  lines  leading  to  coils 
used  for  heating  tanks,  digesters,  etc.,  and  engines.  The  cold 
liquid  surrounding  the  coil  may  condense  the  steam  so  perfectly 
as  to  cause  the  formation  of  a  vacuum.  The  water  will  then  be 
shot  through  the  pipe  at  a  very  high  velocity,  causing  tremendous 
hammering  and  vibration.  This  effect,  on  a  smaller  scale,  is 
probably  familiar  to  all  of  our  readers  who  have  steam  heating 
systems  in  their  homes. 

To  avoid  condensation,  all  pipe  should  pitch  in  the  direction 
of  the  flow  of  the  steam,  and  if  this  is  impossible,  a  trap  or  drain 
should  be  installed.  All  main  headers  and  manifolds  should  end 
in  a  drain  pocket  connected  to  the  drainage  system.  Branch  lines 
should  be  taken  from  the  top  of  headers,  when  possible,  never 
from  tbe  bottom.  Separators  should  be  placed  in  the  line  leading 
to  each  engine  or  evaporator  or  other  steam  consuming  unit,  as 
near  the  unit  as  possible,  and  all  such  separators  should  be  con¬ 
nected  to  tbe  drainage  system.  Care  should  be  exercised  that 
valves  and/Other  fittings  do  not  form  water  pockets.  Globe  valves 
should  always  be  set  with  the  stem  horizontal ;  gate  valves  may 
be  set  with  the  spindle  vertical  or  at  an  angle.  All  meters,  etc., 
should  be  provided  with  by-passes. 

Piping  should  always  be  arranged  so  that  there  are  no  un¬ 
usual  strains  due  to  expansion  and  contraction.  In  supporting 
the  piping  certain  points  may  be  fastened  firm,  or  anchored,  and 
the  expansion  and  contraction  between  these  fixed  points  taken 
care  of  with  expansion  joints,  bends  and  sliding  supports.  Sys¬ 
tems  have  been  devised  where  all  the  supports  are  of  the  sliding 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  393 

variety.  All  supports  should  be  from  the  building  and  not  from 

equipment.  ,  . 

It  is  frequently  a  good  plan  to  have  a  distinctive  color  of 
paint  for  all  the  diiferent  lines  carrying  water,  steam,  acid,  stock, 
bleach,  vacuum,  etc.  Thus  any  part  of  any  line  can  be  immedi¬ 
ately  distinguished  wherever  it  is  met  with  in  the  mill.  The  same 
system  of  colors  can  be  adhered  to  in  the  drafting  room.  No 
piece  of  steam  heated  equipment  should  ever  be  set  up  without 
some  provision  for  taking  care  of  excess  pressure,  such  as  a  good 
safety  valve. 

Pumps. 

A  complete  description  of  all  the  various  types  of  pumps  used 
in  pulp  and  paper  plants  would  require  a  book  in  itself.  More¬ 
over,  excellent  works  now  exist  on  the  theory  and  practice  of 


Courtesy:  Goulds  Mfg.  Co.,  Seneca  Falls,  N.  Y. 

Fig.  149. — Typical  triplex  plunger  stuff  pump. 


both  plunger  and  centrifugal  pumping  equipment,  as  well  as  on 
the  general  subject  of  hydraulics  and  hydrod)'namics.^  Conse¬ 
quently,  we  will  only  touch  on  the  matter  very  briefly  here.  T  he 
pumping  equipment  required  in  the  boiler  house  is  dealt  with 
in  the  special  chapter  on  that  subject. 


1  Among  other  works  we  might  suggest:  W.  M.  rtv— “Cen- 

ward  Butler— “Modern  Pumping  and  Hydraulic  Machinery.  ,  .R- 

trifugal  Pumps.”  C.  G.  DeLaval— “Centrifugal  Pumping  Machinery.  A.  M.  Greene 
“Pumping  Machinery.”  E.  W.  Sargeant—  Centrifugal  Pumps.  .  ,  • . 
“.Textbook  on  Hydraulics.”  All  obtainable  from  the  publishers  of  this  book. 


Courtesy:  Goulds  Mfg.  Co.,  Seneca  Falls,  N.  Y. 

Fig-  ISO-  Typical  centrifugal  pnrrn  direct  connected  to  geared  steam 

turbine. 


394  MODERN  PULP  AND  PAPER  MAKING 


Courtesy:  Goulds  Mfg.  Co.,  Seneca  Falls,  N.  Y. 

I'ig.  151.  Horizontal  vacuum  pump  suitable  for  use  with  paper  machines. 

Also,  it  is  well  to  remember  that  a  ptimp  may  be  a  very  fine 
piece  of  machinery  and  still  be  totally  unsuited  for  pulp  and  paper 
mill  work.  Some  of  the  pump  manufacturers  have  sales  engi¬ 
neers  who  have  given  special  attention  to  the  problems  of  paper 
mill  work.  In  any  case  the  buyer  should  examine  all  claims 


Pumps  are  to  the  paper  mill  what  the  heart  is  to  the  human 
system.  Hence  it  is  very  poor  policy  to  install  a  cheap  pump. 
In  fact,  there  is  hardly  any  place  in  the  design  of  a  mill  where 
it  is  more  necessary  to  be  liberal  and  to  play  safe.  The  failure  of 
some  comparatively  insignificant  pump  may  close  down  a  whole 
system  for  hours,  or  even  days. 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  395 

advanced  by  the  pump  manufacturer,  who  (while  meaning  well) 
may  perhaps  not  fully  understand  the  nature  of  the  service  that 
will  be  expected  from  the  pump.  It  is  well  to  stick  to  makers 
who  have  made  somewhat  of  a  specialty  of  pulp  and  paper  mill 
work,  even  if  others  offer  slightly  more  attractive  prices  or  de¬ 
liveries. 

Some  of  the  points  to  look  out  for  in  a  pump  are;  Strength, 
simplicity,  nature  of  material  {i.e.,  if  it  will  resist  the  chemical 
action  of  the  fluid  to  be  pumped),  mechanical  efficiency  {i.e., 
economy  of  power),  durability  and  ease  with  which  repairs  can 
be  made. 

Belting. 

Belting  is  the  most  ordinary  means  of  transmitting  power  in 
pulp  and  paper  mills.  In  order  to  be  of  maximum  efficiency  the 
belting  will  need  to  fill  definite  requirements  of  pliability,  strength, 
durability,  freedom  of  stretch  and  a  surface  that  will  reduce  slip¬ 
ping  to  a  minimum. 

Belting  is  made  from  a  number  of  materials  such  as  leather, 
rubber  (or  more  correctly,  canvas  impregnated  with  rubber), 
canvas,  camel  hair,  etc.  The  selection  of  the  right  variety  of 
belting  for  a  given  set  of  conditions  is  a  matter  of  much  im¬ 
portance.  Leather  belting  is  more  durable  than  any  other,  and  is 
the  most  generally  useful,  but  there  are  some  places  where  it 
cannot  be  used.  Tests  recently  carried  out  by  E.  D.  Wilson^  at 
the  Mellon  Institute,  Pittsburgh,  support  the  following  conclu¬ 
sions:  (i)  Leather  belting  possesses  a  greater  power  transmit¬ 
ting  capacity  than  any  other  belting  material.  (2)  This  advan¬ 
tage  persists  at  all  speeds  up  to  5,000  feet  per  minute.  (3)  The 
relative  capacities  of  the  various  belts  remain  the  same  no  mat¬ 
ter  what  kind  of  pulley  is  used.  (4)  Leather  belting  possesses 
a  higher  overload  capacity  than  other  belting.  (5)  Leather  belt¬ 
ing  is  the  only  type  of  belting  that  improves  with  age,  all  other 
kinds  being  best  when  new.  (6)  Leather  belting  does  not  need 
to  be  as  wide  as  other  belting  to  produce  the  same  effect.  These 
conclusions  are  based  on  tests  of  the  most  exacting  and  scientific 
nature,  and  may  be  accepted  as  correct. 

Rubber  belting  is  chiefly  used  in  very  wet  or  steamy  places. 
Around  screens,  and  any  place  else  where  frequerit  “washing  up  ’ 
has  to  be  done,  rubber  belting  is  generally  desirable.  Rubber 
belting  is  quickly  destroyed  by  oil  or  grease.  Paper  mills  ordi¬ 
narily  being  considered  wet,  sloppy  places,  rubber  belt  is  very 
generally  used  for  all  purposes,  but  in  many  instances  it  would  be 
better  to  use  leather  belting  and  remove  the  cause  of  the  wet¬ 
ness  or  slop.  In  general  it  is  always  better  to  remove  destruc¬ 
tive  conditions,  if  possible,  than  to  allow  them  to  ^  persist  and 
get  a  belt  that  will  stand  them.  For  instance,  if  a  rubber 
belt  seems  desirable  and  cannot  be  used  on  account  of  oil 

^  Paper  Industry,  Sept.,  1919,  pg.  443. 


396  MODERN  PULP  AND  PAPER  MAKING 

dripping  on  it,  it  is  the  most  logical  thing  to  protect  the  belt 
against  the  oil,  not  to  seek  for  a  belt  that  will  stand  up  against 
oil.  Many  times  when  the  wrong  kind  of  belting  is  in  use 
it  is  because  when  the  belt  had  to  be  replaced  none  of  the 
right  kind  was  on  hand,  but  the  wrong  kind  was.  Errors 
of  this  kind  when  once  made  are  often  persisted  in.  It  is 
good  economy  to  have  a  good  stock  of  all  kinds  of  belting  used 
in  the  mill. 

Camel  hair  belting  is  excellent  where  a  belt  is  required  that 
will  resist  acid  and  alkali.  It  does  this  better  than  any  other  kind 
of  belting.  It  also  resists  high  temperatures  that  would  destroy 
leather,  canvas  or  rubber  belting. 

The  following  practical  hints  regarding  the  use  of  belting 
may  be  found  useful : 

1st.  It  is  better  to  select  a  wide  thin  belt  and  a  pulley  with 
a  wide  face,  rather  than  a  narrow  thick  belt  of  the  same  strength. 
The  belt  can  then  be  run  looser  without  slipping  as  it  has  more 
contact  surface.  For  example — A  12  in.  4-ply  belt  of  the  same 
strength  as  a  6  in.  2-ply  would  be  much  better  to  use,  since 
it  has  twice  as  much  surface  of  contact  with  a  pulley  and  does 
not  have  to  be  run  so  tight  to  prevent  it  from  slipping.  A 
thin  4-ply  belt  is  also  much  less  liable  to  buckle  when  going 
around  a  small  pulley  whereas  a  thick  8-ply  is  stretched  on  the 
outside  and  buckled  on  the  inside,  thereby  considerably  shorten¬ 
ing  its  life. 

2nd.  It  is  better  to  have  a  belt  run  loose  than  tight.  If 
a  belt  has  to  be  drawn  “fiddle  string”  to  make  it  transmit  power 
properly  without  slipping  or  if  a  sticky  dressing  has  to  be  ap¬ 
plied  to  prevent  it  from  slipping  when  run  only  moderately 
tight  it  is  a  positive  indication  that  the  belt  is  too  narrow  and  a 
wider  one  substituted  even  if  broader  faced  pulleys  have  to  be 
put  on.  In  certain  cases  where  it  is  necessary  to  shift  a  belt 
as  elevators  and  cone  pulleys,  the  edges  of  the  belt  are  sub¬ 
jected  to  much  wear.  In  such  cases  a  thick,  hard  belt  will  last 
longer  than  a  broad  thin  one.  Sometimes  a  very  firm,  hard, 
stiff  belt  is  better  to  use  than  a  soft,  pliable  one;  judgment  in 
such  cases  is  necessary  to  decide  what  to  use. 

With  belting  of  the  proper  size  and  pulleys  of  the  proper 
width  of  face  to  transmit  the  power  required  of  them  the  belt 
ought  to  run  moderately  slack  without  slipping.  The  use  of 
“dressing”  should  be  resorted  to  only  as  a  temporary  remedy 
for  a  slipping  belt  and  should  not  be  indulged  in  as  a  general 
practice. 

Rosin  should  never  be  put  on  a  belt  to  prevent  slipping  as 
it  is  very_  injurious  and  its  action  is  only  temporary.  For  this 
reason  a  small  supply  of  dressing  should  always  be  kept  on 
hand  to  use  in  case  of  emergency  to  prevent  the  necessity  of 
having  the  rosin.  The  surface  of  belts  and  faces  of  pulleys 
should  be  kept  clean  and  smooth.  All  accumulations  or  lumps 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  397 

on  pulleys  should  be  removed  and  the  surface  of  belts  be  kept 
smooth  not  by  “scraping”  unless  absolutely  necessary  but  % 
wiping  or  washing. 

A  running  belt  can  be  very  nicely  wiped  by  holding  on  it 
a  rag  wet  with  gasolene. 

A  leather  belt  running  under  the  proper  conditions  seldom 
requires  any  treatment.  If  it  is  running  in  a  very  dry  place 
and  seems  inclined  to  get  hard,  an  occasional  application  of 
castor  oil  both  inside  and  outside  will  keep  it  soft  and  pliable. 
Wool  fat  or  degras  is  also  excellent  for  this  purpose,  but  such 
treatment  should  not  be  repeated  too  frequently  so  as  to  make 
the  leather  too  soft  and  greasy  as  it  then  becomes  “stretchy” 
and  loses  to  some  extent  its  firmness  and  strength.  All  that 
should  be  done  is  to  use  an  occasional  dose  of  castor  oil  or  wool 
fat  just  sufficient  to  keep  the  leather  from  getting  harder  than 
it  was  when  new  and  to  keep  the  surface  “velvety”  when  it  ap¬ 
pears  to  be  getting  a  trifle  too  hard  and  glassy. 

Rubber  belting  is  more  sensitive  to  the  use  of  dressing 
than  leather  and  it  requires  considerable  care  and  attention  to 
keep  a  rubber  belt  in  good  condition. 

The  natural  rubber  with  which  a  rubber  belt  is  covered  is 
the  best  contact  surface  that  can  be  had  so  long  as  it  is  kept 
in  good  condition.  When  the  white  powder  with  which  a  new 
rubber  belt  is  coated  is  rubbed  oflf,  exposing  the  soft  velvety 
surface  of  the  rubber,  this  presents  almost  an  ideal  contact 
surface  of  a  pulley.  All  that  is-  necessary,  therefore,  is  to  keep 
this  rubber  surface  in  its  natural  condition  for  as  long  a  time  as 
possible. 

When  the  inside  surface  .of  a  rubber  belt  appears  to  be 
somewhat  too  hard  or  glassy  it  is  best  to  clean  it  with  a  rag 
and  gasolene,  then  apply  a  very  small  amount  of  linseed  oil. 
The  best  way  is  to  moisten  a  rag  with  the  oil.  By  passing  the 
rag  lightly  across  the  belt  while  it  is  running,  only  a  film  of  oil 
gets  onto  the  belt. 

The  rag  should  not  be  soaked  to  such  an  extent  that  too 
much  would  get  on  the  belt  at  one  time.  The  object  is  only  to 
get  a  trace  of  oil  on  the  surface  of  the  belt,  so  as  to  take  off  the 
“glassy”  surface  and  have  the  rubber  surface  velvety  or  in  its 
natural  condition.  If  too  much  is  applied  the  belt  will  slip  until 
the  oil  soaks  into  the  pores,  and  by  soaking  in  too  much  oil 
the  life  of  the  rubber  coating  is  injured  and  it  becomes  more 
or  less  rotten.  The  object  is.  therefore,  to  take  off  only  the 
“glase”  and  form  only  a  film  of  soft  rubber  in  its  place. 

It  should  not  penetrate  the  rubber  and  soften  it  as  castor 
oil  or  wool  fat  does  to  a  leather  belt. 

Stretched  cotton  belts  stuffed  with  grease  require  only  to  be 
kept  clean  and  free  from  accumulations  of  dirt  the  same  as 
any  belt,  and  to  be  kept  in  a  soft  greasy. ^condition,  by  the  ap¬ 
plication  of  oil.  As  before  stated,  they  are  the  best  variety  of 


398  MODERN  PULP  AND  PAPER  MAKING 

belt  to  use  in  places  where  oil  gets  on  them.  This  would  soon 
ruin  a  leather  or  rubber  belt,  but  is  beneficial  to  this  kind  of 
a  belt. 

The  ideal  belt  drive  is  horizontal.  However,  such  a  drive  is 
exceptional,  and  the  best  has  to  be  made  of  other  conditions. 
In  driving  beaters  and  other  such  equipment  it  is  advisable  to 
have  the  belt  wrap  around  the  driven  pulley  as  far  as  possible. 
With  a  horizontal  drive,  this  is  partially  accomplished  by  al¬ 
lowing  the  upper  strand  of  the  belt  to  run  slack.  This  ar¬ 
rangement  is  not  desirable  in  driving  beaters,  as  space  and 
economy  of  belting  do  not  permit  of  such  drives.  The  same  effect 
can  be  secured,  and  improved  on,  by  an  idler  pulley,  as  shown  in 
the  illustration.  The  best  known  of  these  devices  is  the  “Lenix” 


From:  "The  Paper  Industry.”  Chicago,  III. 

F'g-  ^5^-  Diagram  showing  belt  drive  for  heater  or  other  similar  equip¬ 
ment,  illustrating  use  of  idler  pulley. 

which  was  invented  by  a  French  artillery  officer  and  is  now  used 
in  connection  with  all  kinds  of  machinery.  An  article  describing 
this  device  in  great  detail  will  be  found  in  “Paper  Industry” 
for  January,  1920,  pg.  853,  by  V.  Sahmel. 

In  driving  beaters  the  Lenix  device  is  frequently  used  in 
the  following  manner ;  The  lineshaft  is  arranged  vertically 
below  the  shaft  of  the  beater  pulleys.  The  Lenix  device  is 
operated  by  means  of  a  hoisting  rig  from  the  beater  floor  in  such 
a  way  that  when  it  is  desired  to  stop  the  beater  the  resilient  idler 
pulley,  or  Lenix,  is  thrown  back.  When  it  is  desired  to  start 
up  the  beater,  the  Lenix  is  thrown  forward  so  as  to  engage  the 
full  width  of  the  belt  with  the  driving  pulley.  This  accom¬ 
plishes  the  same  effect  as  the  ordinary  tight  and  loose  pulley 
arrangement,  but  is  much  better  for  the  belt.  With  the  tight 
and  loose  pulley  arrangement  the  full  starting  load  is  carried  by 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  399 

one  edge  of  the  belt  and  the  other  edge  tends  to  become  bruised 
by  the  belt  shifting  fork. 

Unless  a  great  deal  of  money  is  to  be  wasted  belting  must  be 
figured  very  carefully.  Speeds  of  driving  and  driven  pulleys 
should  be  taken  with  a  speed  counter  and  over  a  long  period 
of  time.  The  old  formulas,  such  as  the  one  that  “the  horse¬ 
power  to  be  transmitted,  multiplied  by  800  and  divided  by  speed 
of  the  belt  in  feet  per  minute  would  give  the  width  of  the 
belt  in  inches,”  are  not  to  be  trusted  in  these  days  of  high 
priced  belting.  They  are  all  figured  so  as  to  give  a  generous  fac¬ 
tor  of  safety  and  will  frequently  result  in  much  wider  belts  being 
selected  than  there  is  any  need  for. 

Rope  Drives. 

Rope  drive  is  quite  extensively  used  in  pulp  and  paper  mills, 
especially  for  machine  drive.  For  general  purposes  this  method 
of  drive  is  much  commoner  in  England  than  in  America. 
However,  recently  several  large  paper  machines  have  been 
equipped  with  rope  drive  in  this  country  and  it  is  also  used 
for  driving  beaters,  electric  generators,  etc. 

There  are  two  systems  of  rope  drive,  the  Continuous  and  the 
Multiple.  The  continuous  system  has  been  most  used  in  America 
and  the  multiple  in  England  and  on  the  continent  of  Europe. 
In  the  continuous  system  a  single  rope  is  passed  as  many  times 
around  both  driving  and  driven  pulleys  as  there  are  grooves 
to  be  filled,  and  is  then  carried  across  the  whole  width  by 
means  of  tension  pulleys.  This  system  is  very  useful  where 
drives  have  to  be  carried  around  corners  or  angles.  In  the 
multiple  system  there  are  as  many  rope  belts  as  there  are 
grooves  on  the  pulley.  This  system  has  the  advantage  that  if 
one  strand  breaks  the  rest  will  carry  on  the  work  until  a  suit¬ 
able  opportunity  arrives  to  remedy  the  defect.  ^ 

Users  of  rope  drive  claim  that  it  is  much  more  efficient 
than  belt  drive.  Belts  depend  entirely  on  friction  for  their 
grip  on  the  pulley.  Moreover,  a  film  of  air  is  always  caught 
between  the  belt  and  the  pulley,  which  tends  to  cause  slipping. 
The  rope  runs  in  a  groove  so  cut  that  the  rope  takes  a  firm 
hold  on  the  groove,  but  does  not  fill  it  entirely,  the  air  passing 
freely  out  through  the  open  space  under  the  rope.  Finally,  the 
best  cotton  rope  is  cheaper  than  an  equivalent  amount  of  leather 
belting.  Cotton  rope  is  preferable  for  rope  drives,  although 

manila  has  been  used.  _ 

In  driving  paper  machines  by  rope  drive  a  large  grooved  ny 
wheel  is  placed  in  the  basement  under  the  dryer  part  of  the 
machine.  From  this  wheel  ropes  lead  up  and  down  the  base¬ 
ment,  conveying  power  to  short  counter-shafts  situated  in  the 
basement  under  the  several  roll  shafts  of  the  paper  machine. 
Upon  these  counter-shafts  below  and  roll  shafts  above  are  the 
cones,  between  which  power  is  transmitted  by  a  loose  be  t 


400  MODERN  PULP  AND  PAPER  MAKING 

with  a  tightener  pulley.  The  advantages  claimed  for  this  method 
of  drive  are  the  doing  away  with  bevel  gearing  and  the  long  main 
line  shaft,  avoiding  the  loss  of  power  usually  occasioned  by  the 
numerous  bearings  of  this  shaft. 

Ventilation. 

When  we  consider  that  paper  leaves  the  paper  machine 
containing  approximately  5  per  cent  moisture,  whereas  the 
stock  from  which  the  paper  is  made  is  nearly  100  per  cent 
water,  and  when  we  recollect  further  that  55  or  60  per  cent  of 
the  water  is  removed  as  vapor  in  the  dryer  part  of  the  ma¬ 
chine,  we  are  in  a  position  to  attribute  some  importance  to 
ventilation  in  the  paper  mill. 

Moreover,  at  the  wefend  of  the  machine  there  is  a  certain 
amount  of  moisture  from  the  stock  flowing  over  the  wire,  the 
various  showers,  etc.  Also,  the  air  of  the  beater  room  and  other 
parts  of  the  mill  is  moist.  If  a  pond  is  used  in  the  wood  room 
it  gives  off  vapor,  especially  in  winter  when  the  temperature 
of  the  water  is  raised  to  remove  ice  from  the  wood.  Finally, 
in  the  digester  house  there  are  sulphur  fumes  and  moisture,  and 
in  the  bleaching  room  there  is  chlorine. 

There  are  two  main  effects  to  be  considered  in  discuss¬ 
ing  the  ventilation  (or  lack  of  it)  of  a  paper  mill.  One  is 
the  effect  on  the  product  and  the  other  the  effect  on  the  work¬ 
men. 

Moisture,  if  not  carried  off,  will  condense  on  roofs,  girders, 
piping,  etc.,  and  drip  back  on  the  paper  or  into  the  stock.  This 
can  be  avoided  entirely  by  a  proper  system  of  fans  and  heaters 
for  blowing  hot  air  along  the  upper  part  of  the  machine  room. 
The  amount  of  moisture  that  air  will  hold  increases  with  the 
temperature  and  a  comparatively  slight  increase  in  temperature 
will  prevent  all  condensation. 

In  one  of  the  best  systems  for  accomplishing  this  fresh  air 
from  outside  is  drawn  into  a  compartment  filled  with  steam  coils 
which  raise  the  temperature  of  the  air  to  about  71°  F.  By 
means  of  a  blower  and  a  system  of  flues  this  air  is  distributed 
all  along  the  roof  of  the  machine  room.  The  slope  of  the 
roof,  the  design  of  the  hood  placed  over  the  dryers  and  many 
other  factors  (for  instance,  if  one  end  of  the  machine  room  is 
more  exposed  to  cold  winds  than  the  other)  affect  this  problem, 
and  a  careful  study  should  be  made  of  conditions  and  the  com¬ 
bined  _  heating  and  ventilating  system  designed  to  meet  them. 
This  is  far  from  an  unimportant  matter  since  several  tons  of 
moisture  are  given  off  daily  in  a  mill  of  any  size. 

Many  well-meant  attempts  at  ventilation  are  almost  useless, 
because  the  details  of  the  design  have  not  had  the  attention  of 
anyone  competent  to  deal  with  such  problems.  Frequently  the 
fans  for  removing  moist  air  will  be  of  much  greater  capacity 
than  the  system  for  supplying  fresh,  warm,  dry  air.  This  will 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  401 

result  in  cold  air  being  drawn  into  the  building  in  winter 
through  window  frames,  doors,  cracks,  etc.  In  other  cases  an 
unnecessarily  large  volume  of  warm,  dry  air  is  furnished  in 
the  effort  to  do  the  thing  thoroughly  which  is  simply  wasting 
electricity  and  steam  to  no  good  pui-pose.  Hoods  over  dryers 
are  sometimes  not  properly  placed  so  that  every  unusual  draft 
through  the  room  causes  steam  to  be  carried  out  into  the  room. 
Mills  roofs  are  frequently  designed  so  that  moisture  pockets 
form  which  are  full  of  stagnant,  humid  air,  not  reached  at^  all 
by  the  currents  created  by  the  fans.  This  is  an  argument  against 
very  steep  roofs.  If  a  steep  roof  is  necessary  on  account  of  the 
snowfall,  a  ceiling  or  false  roof  should  he  provided,  nearly 
flat,  so  as  to  prevent  pockets  of  moist  air.  However,  it  is 
better  to  avoid  such  ceilings,  as  the  space  between  is  hard  to  ven¬ 
tilate  and  usually  affords  an  opportunity  for  rot  and  decay  to 
attack  the  whole  roof. 

The  lack  of  a  good  ventilating  system  in  the  machine  room 
will  result  in  much  paper  being  damaged  and  the  loss  from  this 
source  in  a  year  or  so  would  pay  for  suitable  ventilating  equip 

ment.  . 

Some  mills  use  steam  pipes  arranged  m  rows  along  the  root 

but  this  system  is  inferior  to  blowing  hot  air  into  the  building 
since  the  moisture  tends  to  collect  and  condense  on  the  walls  and 
elsewhere  and  it  will  gradually  rot  the  window  frames  and 
other  wood  work  and  corrode  the  machinery. 

A  good  ventilating  system  is  a  great  help  in  keeping  the 
product  uniform,  regardless  of  what  the  weather  conditions  may 
be.  There  are  firms  designing  what  is  known  as  air  condition 
ing  equipment,”  which  is  simply  scientifically  designed  ventilating 
equipment,  which  will  guarantee  exactly  the  same  conditions 
of  humidity  and  temperature  the  year  round  regardless  of  what 

the  external  weather  conditions  may  be.  _  11 

Modern  mills  frequently  deliver  heated  air  between  the  dry¬ 
ing  cylinders  of  the  machine  to  carry  off  moisture  as  it  is 
evaporated.  The  volume  of  this  air  must  necessarily  be^  very 
large— from  2^,000  to  100,000  cubic  feet  of  air  per  minute. 
The  air  must  be  hot  enough  to  carry  off  the  moisture  at 
maximum  efficiency,  but  not  hot  enough  to  reduce  the  strei^th 
of  the  paper  being  made.  About  140°  to  150°  F.  is  right  The 
air  is  usually  distributed  through  6-inch  pipes  placed  between 
the  dryers,  one  pipe  for  each  roll.  The  pipes  are  slotted  to  dis¬ 
charge  the  air,  the  slots  running  the  length  of  the  pipe  and 
being  about  6  inches  long  by  fo  inch  wide. 

The  above  remarks  are  all  related  to  the  influence  of  ven¬ 
tilation  on  the  product.  There  is  also  the  effect  on  the  he  p 
to  consider.  Workmen  today  are  not  satisfied  to  work  m  a 
humid,  steamy,  uncomfortable  and  unhealthy  atmosphere  because 
they  know  that  such  conditions  are  preventable  and  unnecessary. 
Moreover,  even  if  they  will  remain  on  the  job  m  such  a  mill. 


402  MODERN  PULP  AND  PAPER  MAKING 

they  cannot  do  as  good  work  as  if  the  working  conditions  were 
more  agreeable. 

Adequate  provision  for  ventilation  is  especially  necessary  for 
obvious  reasons,  m  rooms  where  waste  paper  and  rags  are  beine 
sorted,  dusted,  cut  and  otherwise  prepared  for  use  In  old- 
fashioned  establishments  this  work  was  frequently  carried  out 
in  dark,  tin  ventilated,  evil  smelling  holes,  unfit  for  any  person 
to  work  in.  The  rag  sorting  rooms  of  the  modern  paper  mills 
using  rags  are  clean  and  sanitary  enough  to  eat  a  meal  in. 
JNot  only  has  this  change  made  the  work  much  better  from  a 
SMitary  and  humane  point  of  view,  but  it  results  in  increased 
efficiency  on  the  part  of  the  workers. 

Portions  of  the  mill  where  bleach  is  being  handled  should  be 
provided  with  good  ventilating  systems  and  the  fans  and  air 
passages  should  be  protected  against  the  action  of  chlorine 
vapors,  which  rapidly  corrode  metal  work.  There  are  a  number 
ot  paints  and  lacquers  which  are  more  or  less  resistant  to 
chlorine,  but  for  fans  the  most  satisfactory  material  is  rubber 
covered  iron.  The  metal  work  of  the  fan  is  covered  with  a 
rubber  coating  by  the  same  process  whereby  rolls  are  given 
their  rubber  coverings.^  Lead  coating  or  galvanizing  will  not 
stand  up  against  chlorine  and  its  compounds.  Some  form  of 
gas  mask  or  respirator  ought  to  be  at  hand  for  use  in  case  of  a 
break  down  of  the  ventilating  system  and  for  making  repairs.  In 
tact,  such  equipment  will  come  in  useful  in  many  parts  of  the 
paper  mih— in  the_  digester  house,  blow  pits,  acid  plants,  around 
^Iphur  burners,  m  case  of  fire  in  any  part  of  the  mill,  etc. 
Gas  masks  of  high  efficiency  originally  designed  for  military 
purposes  are  now  offered  for  sale  by  several  firms.  These 
are  much  better  than  ordinary  respirators  which  withhold  dust 
and  similar  material  but  not  chemical  vapors  or  smoke. 

_  Another  place  where  proper  ventilation  is  very  needful  is 
m  the  grinder  room  of  ground  wood  mills.  It  is  almost  as 
necessary  to  have  hoods  over  the  grinders,  or  some  other  ade¬ 
quate  means  of  ventilation,  as  in  a  machine  room,  and  grinder 
room  roofs  will  frequently  be  found  in  a  very  bad  state  of  repair 
through  Ignoring  this  fact.  ^ 

J°^^owing  hints  on  the  design  of  a  ventilating  system  are 

nf  M  r-11  Forest  Products  Laboratories 

of  Canada,  McGill  University,  Montreal. 

_  In  the  design  of  a  ventilating  system  the  first  thing  to  re¬ 
ceive  att^tion  IS  the  amount  of  moisture  which  will  leave  the 
dryers,  ^or  a  machine  room  this  figure  may  be  determined  by 
finding  the  difference  between  the  moisture  of  the  sheet  as  it 
goes  onto  and  leaves  the  dryers  along  with  the  output  of  the  mill 
or  any  stated  mtervak  It  is  also  necessary  to  know  the  amount 
of  moisture  m  the  air  as  taken  into  the  mill.  Knowing  the 

enters  and  leaves  the  room,  one 

’The  Paper  Industry.  February,  1920,  pg.  1005. 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  403 


can  find  with  the  help  of  Psychrometric  Tables  what  amount  of 
moisture  may  possibly  be  carried  by  any  volume  of  air,  A 
safe  margin  should  be  held  so  that  one  does  not  figure  upon  the 
air  leaving  the  mill  saturated  with  moisture.  An  idea  of  the 
amounts  of  moisture  which  may  be  held  by  air  at  various  tem¬ 
peratures  and  various  degrees  of  saturation  is  given  in  the 
following  table,  where  the  data  given  has  been  selected  _^or 
estimated  from  the  complete  tables  contained  in  “Psychrometric 
Tables”  by  C.  F.  Marvin,  of  the  Weather  Bureau,  U.  S.  De¬ 
partment  of  Agriculture,  Government  Printing  Office,  Wash¬ 
ington,  1915. 

AMOUNTS  OF  MOISTURE  HELD  BY  AIR  AT  DIEFERENT 
RELATIVE  HUMIDITIES 


Grains  of  water  in  suspension  per  cubic  feet  of  air 
PERCENTAGE  OF  SATURATION 


Tempera¬ 
ture  F.° 

10% 

40% 

— 20 

0.017 

0.066 

— 20 

0.028 

0.114 

0 

0.048 

0.192 

10 

0.078 

0.310 

20 

0.124 

0.494 

30 

0.194 

0.774 

40 

0.285 

1. 140 

50 

0.408 

1.630 

60 

0.574 

2.298 

70 

0.798 

3.192 

80 

1.093 

4-374 

90 

1.479 

5-916 

100 

1.977 

7.906 

110 

2.611 

10.445 

70% 

95% 

100% 

0.116 

0.157 

0.166 

0.200 

0.270 

0.285 

0.337 

0.457 

0.481 

0.543 

0.736 

0.776 

0.864 

1. 173 

1.235 

1.354 

1.836 

1.935 

1.994 

2.703 

2.849 

2.853 

3.870 

4.076 

4.022 

5-459 

5-745 

5-586 

7-578 

7.980 

7.654 

10.378 

10.934 

10.353 

14045 

14.790 

13-836 

18.765 

19.766 

18.278 

24.806 

26.112 

As  soon  as  one  has  determined  how  much  moisture  will  be 
carried  by  any  definite  amount  of  moving  air,  and  knowing  the 
amount  of  moisture  in  it  at  the  start,  he  can  find  what  volume 
of  air  should  pass  through  the  system  at  any  given  time.  The 
simplest  way  of  finding  if  the  ventilating  system  is  sufficient 
may  be  noted  by  the  presence  or  absence  of  condensation  in 
any  part  of  the  mill  after  the  system  has  been  running  for  some 
time  with  all  doors  and  windows  closed.  The  presence  of  any 
condensation  would  show  one  of  two  things :  either  that  more 
air  should  be  moving  through  the  ventilating  pipes,  or  else 
that  the  air  should  be  heated  to  a  higher  temperature.  Any 
of  these  systems  should  be  built  so  that  the  capacity  may  easily 
be  changed  to  correspond  with  varying  degrees  of  weather  so 
that  much  more  dry,  warm  air  may  be  sent  into  the  mill  on 
a  very  cold  or  a  very  moist  day  than  on  a  day  when  the 
weather  is  moderate. 

A  system  designed  in  this  way  should  be  satisfactoryg  as  re 
gards  condensation  on  the  ceiling  of  the  room,  but  it  w^ould 
not  be  sufficient  to  prevent  condensation  in  concealed  places 
between  roof  planks  and  the  roofing  paper.  In  all  probability 


404  MODERN  PULP  AND  PAPER  MAKING 

it  would  not  be  economical  to  attempt  such  a  result  with  ven¬ 
tilation  alone,  but  by  following  a  scheme  of  roof  construction 
especially  designed  to  take  care  of  these  difficulties,  the  danger¬ 
ous  condition  may  be  avoided.  Such  construction  consists  in 
Isome  proper  use  of  insulating  material  in  connection  with 
the  roof. 

Problem. ^  How  much  air  should  be  used  to  ventilate  a  ma¬ 
chine  room  in  a  paper  mill  where  seventy-two  tons  of  water  are 
evaporated  by  the  dryers  in  twenty-four  hours?  The  weather 
is— -20°,  the  relative  humidity  is  75%,  and  the  air  used  in  ven¬ 
tilation  leaves  the  mill  at  110°. 

Solution.  Moisture  sent  into  the  room  by  the  dryers:  72 
tons  per  24  hrs.  3  tons  per  hr. ;  i.  e.,  100  lbs.  per  minute  =  700,- 
000  grains  per  minute. 

The  fresh  air  at  70%  relative  humidity  and  at  — 20°  taken  in 
for  heating  and  ventilating  the  mill  contains  0.116  grains  of  water 
per  cubic  foot  (see  tables)  ;  suppose  this  air  leaves  the  mill  at  a 
relative  humidity  of  95%  when  heated  to  110°.  It  is  then  carry¬ 
ing  24.806  grains  of  water  per  cubic  foot.  In  passing  through 
the  mill  it  has  taken  up  24.806  —  0.116  =  24.690  grains  of  mois- 

700,000 

ure  per  cubic  foot.  Then  it  will  require - —  28,351  cubic 

24.69 

feet  of  air  per  minute  to  ventilate  this  machine  room. 

The  question  of  the  distribution  of  steam  to  the  heating  and 
ventilation  system  is  further  dealt  with  in  the  chapter  on  the 
power  plant. 

Lighting. 

Of  recent  years  mill  lighting  has  advanced  to  such  an 
extent  that  there  now  is  a  new  class  of  technical  men  known  as 
illuminating  engineers.  The  need  for  good  light  in  a  paper 
mill  is  almost  too  obvious  to  mention,  but  the  most  economical 
method  of  securing  good  lighting  is  far  from  simple.  Moreover, 
frequently  the  wish  to  provide  good  lighting  is  not  coupled  with 
the  knowledge  of  how  to  do  it  and  illuminating  units  are  placed 
in  unsuitable  places  where  they  are  detrimental  rather  than  useful. 
Pow^ful  illumination  is  not  necessarily  good  illumination .  Good 
lighting  implies  exactly  the  right  amount  of  light  of  the  right 
quality  at  the  right  place. 

H.  T.  Spaulding,  in  a  paper  read  before  the  American  Pulp 
and  Paper  Mill  Superintendents’  Association,  July,  1919,  Green 
Bay,  Wis.,  gives  the  following  list  of  etfects  of  good  lighting: 

‘T.  Reduction  of  accidents. 

2.  Greater  accuracy  in  workmanship. 

3.  Decreased  spoilage  of  product. 

4.  Increased  production  for  the  same  labor  cost. 

5.  Less  eye  strain. 

6.  Better  working  and  living  conditions. 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  405 

7.  Greater  contentment  of  workmen. 

8.  Better  order,  cleanliness  and  neatness  in  the  plant. 

9.  Easier  supervision  of  the  men. 

“In  this  list  it  will  be  noted  that  items  5,  6,  7,  8  and  9  have 
a  bearing  on  accident  prevention.  R.  E.  Simpson  of  the  Travel¬ 
ers  Insurance  Company  in  a  paper  presented  before  the  Illuminat¬ 
ing  Engineers’  Society,  October,  1918,  states;  ‘A  survey  of 
91,000  accidents  from  the  records  of  the  Travelers  Insurance 
Company  for  the  year  1910  showed  that  23.8  per  cent  were  due 
to  improper  or  inadequate  illumination.’  The  same  authority 
explains  that  it  is  hardly  possible  that  this  percentage  prevails 
at  the  present  time,  due  to  progress  in  illumination,  but  he  goes 
on  to  say :  ‘There  is  some  foundation,  however,  for  assuming 
that  18  per  cent  of  our  industrial  accidents  are  due  to  defects 
in  the  lighting  installation.’  ” 

As  a  result  of  the  investigation  of  lighting  by  insurance 
companies,  engineers  and  others,  several  states  have  adopted 
lighting  regulations  and  the  state  of  Wisconsin  maintains  an 
Industrial  Lighting  Commission  to  see  that  factory  lighting  in 
that  state  is  in  conformity  with  modern  ideas. 

The  insurance  companies,  the  manufacturers  of  lighting  equip¬ 
ment  and  various  government  agencies  will  all  be  found  will¬ 
ing  to  help  those  who  wish  to  have  the  best  lighting  at  the  lowest 
cost. 

There  are  many  points  that  seem  of  minor  importance  at  first 
sight,  which,  if  remedied,  will  do  much  to  improve  the  lighting 
system.  Lights  are  frequently  hung  too  high  or  too  low  to 
properly  illuminate  the  work  without  glare.  In  many  cases 
some  system  of  indirect,  or  semi-indirect  lighting  will  avoid 
shadows,  which  are  especially  annoying  around  complicated 
machines.  In  some  cases  the  glare  from  a  brightly  polished 
portion  of  a  piece  of  machinery  is  a  constant  source  of  annoy¬ 
ance.  This  can  often  be  remedied  by  painting  the  portion  offend¬ 
ing,  or  if  this  is  not  possible,  by  changing  the  position  of  the 
light.  Steady  reflection  of  light  from  a  moderately  polished 
surface,  such  as  the  surface  of  a  sheet  of  highly  finished  paper, 
is  very  exhausting  to  the  eyes  in  time.  This  can  be  improved 
by  having  a  more  diffiused  source  of  light.  Where  color  is  of 
importance  lamps  should  be  chosen  which  modify  the  natural 
quality  of  the  electric  light  so  as  to  make  it  more  nearly  re¬ 
semble  daylight.  These  lamps  are  readily  obtainable  today  and 
not  only  permit  of  close  matching  of  colors,  but  also  are  more 
restful  and  agreeable  to  the  eyes. 

Where  matching  of  colors  has  to  b£  carried  out  with  great 
exactness,  special  color  matching  outfits  can  be  obtained  which 
exactly  simulate  daylight.  Around  paper  machines  and  other 
equipment,  portable  lights,  protected  with  wire  screens,  should 
be  available  for  making  adjustments  and  repairs  in  parts  of  the 
equipment  not  reached  by  the  ordinary  illumination. 


4o6  modern  pulp  AND  PAPER  MAKING 

In  addition  to  satisfactory  artificial  light,  every  eflfort  should 
be  exerted  to  admit  as  much  sunlight  as  possible.  A  maximum 
amount  of  steel  sash  and  glass  in  the  walls  with  overhead  sky¬ 
lights  of  large  extent  is  typical  of  modern  factory  construction 
and  makes  for  increased  efficiency. 

The  liberal  use  of  a  good  white  paint  especially  made  for 
factory  use  so  as  to  stand  moisture,  chemical  fumes,  etc.,  will 
do  wonders  in  increasing  the  effectiveness  of  either  day  light 
or  artificial  illumination. 

Water  Supply. 

In  consequence  of  the  very  large  volumes  of  water  required 
in  pulp  and  paper  manufacture  an  adequate  supply  of  water 
of  a  suitable  degree  of  purity  is  a  matter  of  prime  importance. 

The  quantity  of  water  used  will  vary  greatly  with  the  kind 
of  paper  being  made.  In  a  mill  making  fine  papers  from  rags, 
where  the  stock  is  washed  for  a  long  time  with  a  great  deal  of 
water,  volumes  of  water  will  be  required  that  are  enormous 
in  comparison  with  the  output  of  the  mill.  In  mills  making 
news-print,  wrappings,  etc.,  the  washing  is  not  so  elaborate,  but 
the  greater  volume  of  material  handled  makes  the  volume  of 
water  very  large.  According  to  Griffin  and  Little^  the  volume 
of  water  used  in  making  a  ton  of  paper  is  probably  never  less 
than  50,000  gallons  and  is  sometimes  as  much  as  200,000 
gallons. 

One  mill  making  80  tons  of  bag  and  wrapping  paper  per  day, 
with  which  is  considered  a  sulphite  mill  making  125  tons  of 
unbleached  sulphite  pulp,  uses  approximately  15,000,000  gallons 
of  water  per  day  for  all  purposes. 

^  The  writer  knows  of  one  mill  making  no  pulp,  but  only 
paper  from  rags,  purchased  pulp  and  other  materials,  where 
the  water  consumption  is  approximately  4,500,000  gallons  per 
day.  As  the  mill  only  turns  out  about  25  tons  finished  product 
per  day  this  is  a  large  consumption  of  water,  accounted  for 
by  much  washing  of  rags,  bleached  stocks,  etc. 

If  there  is  any  impurity  in  the  water  it  will  get  into  the 
paper  since  the  fibres  in  the  forming  web  of  paper  on  the  wire 
form  a  regular  filter  that  will  catch  and  retain  any  sediment 
or  coloring  matter. 

There  are  two  kinds  of  coloration  in  water.  Coloration  due 
to  sedirnent,  which  can  usually  be  removed  by  settling  or  by 
coagulation  with  alum  or  sulphate  of  iron  in  settling  tanks  or 
ponds,  and  dissolved  color,  usually  resulting  from  decaying  vege¬ 
table  matter,  such  as  peat  bogs,  which  is  very  hard  to  get  rid  of. 

Hard  water  is  water  containing  mineral  salts  in  solution 
which  are  chiefly  lime  salts,  of  these  the  carbonate  being  the 
most  common.  Rain  water  is  perfectly  soft,  but  as  it  falls 
through  the  atmosphere  it  dissolves  carbon  dioxide  and  this 

’  The  Chemistry  of  Paper  Making,  pg.  330. 


GENERAL  DESIGN  OE  PULP  AND  PAPER  PLANTS  407 

enables  it  to  dissolve  lime  and  other  minerals  out  of  the  soil 
and  rocks  over  which,  or  through  which,  it  runs.  Thus,  almost 
all  water  taken  from  streams,  lakes,  wells,  etc.,  requires  to  be 
softened  before  using. 

In  pulp  and  paper  mills  objection  is  made  to  hard  water  on 
two  general  grounds.  First,  it  should  not  be  used  in  the  boilers. 
Second,  it  is  unsuitable  for  use  in  the  actual  manufacture  of 
pulp  and  paper. 

Considering  the  second  point  first,  if  hard  water  is  used  in 
the  beaters,  an  excessive  amount  of  alum  will  have  to  be  added, 
in  order  to  get  rid  of  the  hardness,  because  no  size  will  be 
precipitated  by  the  alum  until  all  hardness  is  removed  from  the 
water.  Not  only  does  this  use  up  alum,  but  it  also  imparts  an 
element  of  uncertainty  to  the  whole  sizing  operation,  since  the 
hardness  of  the  natural  water  will  vary  from  day  to  day  and 
the  beaterman  will  never  know  exactly  how  much  alum  should 
be  added.  Frequently  beatermen  will  attribute  this  trouble 
to  variations  in  the  chemical  strength  of  the  alum,  but  usually 
the  water  is  aetnally  at  fault. 

Hard  water  is  undesirable  for  washing  any  kind  of  pulp, 
either  after  manufacture,  or  after  bleaching.  In  fact,  it  is  much 
better  if  the  mill  has  a  uniform  supply  of  soft  water  so  that 
no  hard  water  need  be  used  at  all  at  any  stage  of  the  process. 
Since  a  water  softening  system  ought  to  be  installed  anyhow 
for  the  use  of  the  boiler  house,  it  is  a  comparatively  easy  matter 
to  make  it  at  the  same  time  of  sufficient  capacity  to  serve  the 
whole  mill. 

Treatment  of  Boiler  Feed  Water:  It  is  not  possible  within 
the  scope  of  this  work  to  enter  into  detail  on  the  treatment 
of  boiler  feed  water,  a  subject  which  would  require  a  complete 
treatise  in  itself.  It  is  necessary,  however,  to  touch  on  the 
great  importance  of  this  matter  as  a  problem  in  practical  pulp 
and  paper  mill  operation.  Preparation  of  water  for  boiler  feed 
purposes  falls  naturally  into  two  main  classifications.  One  is’ 
the  removal  of  sediment  and  mechanically  suspended  material 
of  all  kinds.  The  other  is  the  softening  of  the  water,  or  the 
removal  of  dissolved  salts  of  lime,  magnesium,  etc.,  which 
tend  to  incrust  or  corrode  the  boilers. 

Hardness  in  boiler  feed  water  is  the  direct  cause  of  scale, 
leaky  flues,  muddy  burning  and  many  of  the  other  troubles 
incident  to  large  scale  steam  production.  It  shortens  the  life 
and  reduces  the  efficiency  of  the  boiler;  increases  the  repair  ex¬ 
pense  and  frequently  causes  inopportune  and  costly  delays  and 
shutdowns.  Most  harmful  of  all,  the  scale,  acting  as  a  thick  and 
effective  insulation  of  the  flues,  causes  an  enormous  increase  in 
the  consumption  of  fuel.  The  fuel  wastage  due  to  the  use  of 
hard  water  may  be  anywhere  from  10  per  cent  to  30  per  cent. 

The  cost  of  boiler  cleaning,  boiler  repairs,  boiler  compounds, 
etc.,  all  due  to  the  use  of  hard  water  is  also  a  big  item  in  the 


4o8  modern  pulp  AND  PAPER  MAKING 

operation  of  a  large  plant.  Boiler  compounds  should  be  viewed 
with  suspicion.  They  are  only  temporary  make-shifts  at  best. 
A  steam  boiler  is  not  designed  as  a  vessel  in  which  to  carry 
out  chemical  reactions,  and  the  constant  adding  of  materials  to 
the  water  in  the  boiler  cannot  help  but  corrode  and  weaken 
the  boiler  itself.  The  aim  should  be  to  supply  as  nearly  as 
possible  pure  water  to  the  boiler,  the  purification  having  been 
effected  in  a  purification  and  softening  plant  outside  the  boiler 
system. 

If  the  reader  will  turn  to  the  advertising  pages  of  any  tech¬ 
nical  periodical,  especially  those  dealing  with  power  plant  en¬ 
gineering,  or  with  the  pulp  and  paper  industry,  he  will  note  the 
advertisements  of  numerous  companies  offering  systems  for  puri¬ 
fying  and  softening  water.  The  fact  that  all  of  these  concerns 
have  systems  installed  at  one  plant  or  another,  the  owners  of 
which  find  satisfactory  for  their  purpose,  seems  to  indicate 
that  there  must  be  more  than  one  method  of  purifying  and 
softening  water  that  is  satisfactory.  It  is  not  within  the  scope 
of  this  book  to  describe  all  these  systems,  but  all  concerns 
exploiting  such  equipment  are  ready  at  all  times  to  supply  ex¬ 
cellent  literature  covering  not  only  their  particular  system,  but 
water  purification  and  softening  in  general.  Which  system  to 
install  must  be  decided  largely  on  a  basis  of  cost  and  prestige 
of  the  manufacturer,  unless  the  reader  is  enough  of  a  chemist 
and  water  purification  engineer  to  decide  on  the  relative  merits 
of  the  different  systems  from  the  data  supplied  by  the  manu¬ 
facturers. 

However,  these  systems  mostly  fall  into  three  classes.  These 
are  (i)  The  Lime  Process  (2)  The  Soda  Process  (3)  The  Lime 
and  Soda  Process. 

Lime  Process:  The  carbonates  of  lime  and  magnesia,  to 
which  the  hardness  of  the  water  is  due,  are  precipitated  with 
slaked  lime  in  solution  (lime  water)  in  some  suitable  form  of 
apparatus,  either  with  or  without  heat. 

Soda  Process:  Soda  ash  (sodium  carbonate)  and  caustic 
soda  (sodium  hydroxide)  are  added  either  alone  or  together  to 
the  water  to  be  softened.  Caustic  soda  is  more  efficient  in  this 
process  than  soda  ash.  This  treatment  is  used  with  water  con¬ 
taining  sulphates  of  lime  and  magnesia.  Barium  hydrate  is 
sometimes  used  instead  of  caustic  soda  or  soda  ash,  or  in  certain 
proportions  with  them. 

Lime  and  Soda  Process:  When  both  sulphates  and  carbon¬ 
ates  of  lime  and  magnesia  are  contained  in  the  water  to  be 
softened,  this  process  is  used.  The  soda  is  added  first,  enough 
being  used  to  consume  all  the  sulphates  present,  and  then  lime 
added. 

Simple  boiling  will  soften  water  if  it  is  merely  afflicted  with 
“temporary  hardness,”  i.  e.,  contains  carbonates  of  lime  and 
magnesia.  If  the  water  possesses  “permanent  hardness,”  i.  e., 


GENERAL  DESIGN  OF  PULP  AND  PAPER  PLANTS  409 

contains  sulphates  of  lime  and  magnesia,  mere  boiling  is  of  no 
avail. 

Zeolite  Process:  There  is  one  other  excellent  method  of  soft¬ 
ening  water— the  zeolite  system,  which  is  the  property  of  the  Per- 
miitit  Company.  This  system  avails  itself  of  the  properties  of  an 
interesting  material  known  as  a  zeolite,  which  automatically  re¬ 
moves  calcium  salts  from  the  water,  yielding  perfectly  soft  water 
from  any  ordinary  source.  In  time  the  zeolite  becomes  exhausted, 
but  can  easily  be  renewed  by  a  simple  treatment.  This  system  is 
in  successful  use  in  many  industrial  plants.  It  is  a  rather  expens¬ 
ive  system  for  use  simply  on  boiler- feed  water,  but  is  ideal  where 
perfectly  soft  water  is  needed  as  in  textile  manufacturing  and 
certain  branches  of  paper  manufacture. 

There  are  some  other  troubles  with  water,  which  are  im¬ 
portant  from  the  power  plant  point  of  view,  besides  ‘hardness.' 

Acidity:  This  may  be  due  to  industrial  waste  dumped  into 
streams  by  chemical  plants,  tanneries,  textile  plants,  smelters, 
other  pulp  mills,  etc.  In  sulphite  mills  there  is  always  a  pos¬ 
sibility,  if  check  valves  do  not  work  properly,  or  in  the  event  of 
indirect  heating  equipment  for  digesters  becoming  leaky,  of 
acid  getting  into  boiler  feed  water.  This  causes  acid  corrosion 
which  creates  more  havoc  even  than  scale.  If  there  is  any 
possibility  of  acid  getting  into  the  boiler  feed  water,  very  fre¬ 
quent  tests  should  be  made  with  litmus,  or  an  electric  device 
may  be  rigged  up  which  will  ring  a  gong  as  soon  as  there  is 
enough  acid  content  in  the  boiler  feed  water  for  a  current  of 
fixed  intensity  to  pass  through  the  water,  the  conductivity  of 
which  is  increased  by  the  acid.  Such  devices  are  much  used  in 
Sweden  and  Finland  where  indirect  cook  is  much  used  in  the 
digester  house. 

Foam:  Microscopic  organisms,  sewage,  industrial  wastes, 
etc.,  are  the  chief  substances  present  in  water  which  cause  this 
trouble.  Filtration,  sometimes  preceeded  by  the  addition  of  a 
coagulating  agent  such  as  alum  or  sulphate  of  iron,  is  the  usual 
cure  for  this  evil. 

Priming:  This  is  the  giving  off  of  steam  in  spurts  and 
belches,  caused  by  excessive  amounts  of  salts  in  solution  in  the 
boiler  feed  water.  Too  much  soda,  added  to  get  rid  of  scale¬ 
forming  impurities,  is  a  frequent  cause  of  this  evil.  Frequent 
blowing  down  of  the  boiler  is  the  usual  remedy  for  this  evil. 
If  this  has  to  be  resorted  to  at  too  frequent  intervals  it  is 
advisable  to  look  about  for  some  new  source  of  water  supply. 

Any  and  all  of  the  systems  of  water  softening  may  be  pre¬ 
ceded  by  a  system  for  clarifying  or  removing  suspended  matter 
and  sediment.  This  usually  consists  of  filter  beds  or  tanks, 
the  use  of  a  coagulating  substance,  such  as  alum  or  ferrous 
sulphate  (sulphate  of  iron)  being  now  quite  general.  Alum, 
in  addition  to  removing  sediment,  will  frequently  remove  dis¬ 
solved  colorations. 


410 


MODERN  PULP  AND  PAPER  MAKING 


None  of  the  above  systems  should  be  confused  with  water 
treatment  for  sanitary  purposes.  Water  may  be  perfectly  crys¬ 
tal  clear,  and  also  perfectly  soft  by  chemical  test,  and,  there¬ 
fore,  entirely  suitable  for  boiler  feed  or  for  making  paper, 
and  yet  contain  large  numbers  of  bacteria  of  the  most  virulent 
nature.  To  purify  water  in  the  sanitary  sense,  as  is  done 
by  towip  and  cities,  extensive  filtration,  accompanied  by  treat¬ 
ment  with  chlorine  or  bleaching  powder,  is  needful. 

So  far  we  have  said  much  about  the  quality  of  water  and 
nothing  about  the  quantity.  The  water  supply  of  a  pulp  and 
paper  mill  should  be  adequate  to  take  care,  not  only  of  the 
normal  needs,  but  also  of  requirements  in  case  of  fire.  There 
should  be  a  storage  tank  of  adequate  capacity  mounted  on  a 
tower  sufficiently  high  to  give  a  satisfactory  nozzle  pressure 
at  the  top  of  the  highest  b^uilding  or  wood  pile  in  the  plant. 
The  water  supply  should  be  connected  with  the  supply  of  the 
town,  city  or  village  (assuming  that  the  plant  is  situated  near 
one)  or  of  some  other  nearby  large  manufacturing  plant,  so 
that  assistance  can  be  rendered  in  case  of  fire  or  explosion  put¬ 
ting  the  power  plant  out  of  commission.  Conversely,  this  en¬ 
ables  the  pulp  and  paper  mill  to  be  of  mutual  service  in  case  of 
emergencies. 

Assuming  that  a  pulp  and  paper  industry  consists  of  a 
ground  wood  rnill,  a  sulphite  mill  and  a  paper  mill ;  should  each 
of  these  have  its  own  main  water  supply,  or  should  there  be 
a  single  pumping  installation?  This  will  depend  entirely  on 
local  conditions, _  the  distance  separating  the  various  parts  of  the 
plant,  etc.  This  is  typical  of  the  engineering  questions  con¬ 
cerning  paper  mills  about  which  no  general  directions  can  be 
given. 

Neither  can  anything  definite  be  stated  with  regard  to  the 
kind  of  pump  to  be  used  for  general  water  supply.  Both  cen¬ 
trifugal  and  plunger  pumps  are  used,  multi-stage  turbine  pumps 
being  very  generally  satisfactory. 


XVI.  The  Power  Plant. 


It  is  not  the  author’s  intention  to  deal  with  the  subject  of 
steam  engineering  in  a  general  way  in  this  chapter.  Rather  is 
it  intended  to  point  out  certain  particular  points  about  the  sub¬ 
ject  which  must  be  given  special  attention  in  the  pulp  and  paper 
plant. 

Steam  engineering  is  a  subject  on  which  many  excellent 
books  have  been  written.  Any  man  working  in  a  pulp  ai]d 
paper  mill  who  hopes  ever  to  rise  very  far  in  the  industry  must 
have  at  least  an  elementary  knowledge  of  the  general  principles 
of  steam  engineering,  and  we  earnestly  recommend  that  all  read¬ 
ers  of  this  book  (unless  already  expert  power  plant  engineers) 
secure  some  good  general  works  on  this  subject  and  study  them 
carefully.  We  would  specially  recommend  the  following  books, 
which  are  accessible  to  anyone  and  are  written  in  a  simple  and 
direct  manner : 

“Steam:  Its  Generation  and  Use,”  Babcock  &  Wilcox  Co., 
New  York. 

“Finding  and  Stopping  Waste  in  Modern  Boiler  Rooms,” 
Harrison  Safety  Boiler  Works,  Philadelphia. 

“How  to  Build  Up  Furnace  Efficiency,”  Jos.  W.  Hays,  Rogers 
Park,  Chicago. 

“Efficiency  in  the  Use  of  Oil  Fuel,”  J.  M.  Wadsworth,  issued 
by  U.  S.  Bureau  of  Mines  and  obtainable  from  the  Government 
Printing  Office,  Washington. 

Kent’s  “Pocket  Book  for  Mechanical  Engineers”  will  be  found 
to  contain  all  the  various  tables  necessary  in  making  power  plant 
calculations  and  will  be  found  a  great  help,  not  only  in  the  power 
plant,  but  throughout  the  mill. 

It  is  a  good  plan  to  keep  a  collection  of  the  catalogs  and  bulle¬ 
tins  issued  by  the  different  concerns  making  stokers,  boilers, 
etc.  These  often  contain  valuable  information  and  most  of  these 
concerns  are  genuinely  interested  in  promoting  boiler  room  effi¬ 
ciency  as  well  as  in  selling  their  equipment. 

The  progressive  pulp  and  paper  mill  superintendent  should 
subscribe  to  such  papers  as  “Power”  and  “Combustion”  and 
should  read  them  carefully,  the  advertisements  as  well  as  the 
reading  matter.  Only  in  this  way  can  one  profit  by  the  latest 
developments  in  power  plant  engineering. 

Pulp  and  paper  plants — sulphite,  soda,  kraft  and  paper  mills 
— run  constantly,  night  and  day,  24  hours  per  day  and  six  days 
per  week.  This  makes  necessary  the  very  best  equipment  and 

411 


412  MODERN  PULP  AND  PAPER  MAKING 

the  very  best  firemen  and  engineers  possible  in  the  power  plant. 
In  order  for  a  plant  to  run  constantly  in  144-hoiir  stretches  with¬ 
out  breakdowns  demands  that  everything  should  always  be  in 
the  best  order. 

However,  after  an  experience  covering  a  little  more  than 
35  years  in^the  pulp  and  paper  industry,  the  writer  has  come  to 
the  conclusion  that  no  department  is  so  frequently  neglected  as 
the  power  plant. 

In  some  mills  the  boiler  house  is  still  called  a  “fire  hole”  and 
around  the  town  one  will  hear  firemen  discussing  it.  Each 


Courtesy:  American  Engineering  Co.,  Philadelphia,  Pa. 

Fig-  153-  Boiler  room  of  pulp  and  paper  mill  before  introduction  of 

automatic  stokers. 

fireman  will  be  bragging  about  how  hard  he  has  had  to  work  and 
how  much  coal  he  has  had  to  shovel  in  a  desperate  effort  to  keep 
steam  anywhere  near  the  proper  working  point. 

Such  conditions  were  more  common  in  the  days  when  auto¬ 
matic  stokers  were  not  so  common  as  they  are  now.  Then 
boilers  were  mostly  flat  or  hand  fired.  Of  course,  this  method, 
if  well  conducted,  can  be  made  to  yield  tbe  bighest  possible 
economy,  but  owing  to  tbe  bigb  cost  of  labor  and  (for  that 
matter)  tbe  scarcity  of  it  at  any  price,  people  bave  encouraged 
and  urged  the  use  of  automatic  appliances,  which  have  been  de¬ 
veloped  to  a  high  point,  and  any  saving  that  would  exist  with 
hand  firing  is  more  than  offset  by  the  high  cost  of  such  firing. 


THE  POWER  PLANT 


413 


It  has  been  customary  in  most  mills  to  make  necessary  re¬ 
pairs  to  the  boiler  plant  on  Sundays,  the  only  time  when  they 
well  could  be  made.  The  writer  has  frequently  been  forced  to 
believe  that  executives,  although  interested  in  plant  economy,  do 
not  have  the  necessary  technical  or  practical  knowledge  to 
analyze  the  boiler  room  conditions  personally,  so  that  the  burden 


Courtesy:  American  Engineering  Co.,  Philadelphia,  Pa. 


Fig.  154. — Boiler  room  of  same  plant  as  shown  in  Fig.  153  after  introduc¬ 
tion  of  automatic  stokers. 

falls  on  the  operating  engineer,  and  in  many  such  instances 
either  the  owners  need  a  new  engineer  or  else  the  engineer  needs 
a  new  boss.  There  are  many  plants  where  the  superintendent  is 
constantly  being  nagged  because  of  the  high  cost  of  production 
where  the  blame  can  all  be  traced  to  the  boiler  plant. 

Those  responsible  for  a  modern  pulp  and  paper  mill  should 
not  hesitate  to  provide  all  approved  boiler  plant  accessories.  The 
plant  should  be  equipped  with  indicating  and  recording  instru¬ 
ments  and  these  instruments  should  be  made  use  of.  Water 
should  be  metered.  Flue  gases  must  be  tested.  All  these  things 
must  be  done  regularly  and  systematically  to  know  whether  the 
plant  is  being  operated  on  an  economical  basis  or  not. 

A  steam  plant  serving  a  paper,  sulphite,  kraft  or  soda  mill 


414  MODERN  PULP  AND  PAPER  MAKING 

does  not  differ  essentially  from  any  other  up-to-date  steam  plant, 
except  that  in  the  case  of  the  chemical  pulp  mills  the  steam 
plant  is  frequently  called  on  for  sudden  and  unusual  steam  pres¬ 
sures  on  account  of  the  intermittent  operation  of  the  digesters. 
Whenever  the  digesters  are  filled  and  ready  to  steam  the  inlet 
valve  is  opened.  These  valves  are  not  usually  less  than  4  inches 
in  diameter,  so  it  will  be  seen  that  this  is  a  rather  sudden  and 
drastic  call  on  the  boiler  plant,  and  if  the  boiler  plant  is  not 
able  to  meet  these  requirements  to  the  full  a  great  deal  of  trouble 
will  be  caused. 

In  modern  pulp  and  paper  plants  sulphite,  soda  or  kraft  (any 
or  all  of  these)  is  made  in  the  same  plant  where  paper  is  made. 
Also  there  may  be  rag  pulp  made  and  bleaching  carried  on.  All 
these  processes  comprise  a  single  plant  in  many  cases  and,  natu¬ 
rally,  one  boiler  plant  serves  them  all. 

Paper  manufacturing  is  a  steady  operation  and  does  not  call 
for  extreme  overloads  of  power ;  the  speed  must  be  uniform  and 
the  steam  pressure  constant  in  order  to  make  uniform  and  stand¬ 
ard  weights  of  paper,  so  that  if  the  paper  mill  steam  supply  is 
taken  from  the  same  boiler  plant  as  the  sulphite  mill,  for  instance, 
any  uneven  pressure  or  unusual  load  caused  by  the  operation  of 
the  digesters  is  reflected  in  the  paper  mill  by  causing  the  steam 
engines  which  run  paper  machines  to  slow  down  or  speed  up  as 
the  case  may  be  and  there  is  hardly  any  limit  to  the  harm  such 
a  contingency  can  create. 

There  is  no  real  thorough-going  cure  for  this  except  to  have 
the  paper  mill  supply  from  a  separate  set  of  boilers  and  a  sepa¬ 
rate  steam  line,  and  in  some  cases,  this  is  being  done.  The  next 
best  solution  is  to  have  good  co-operation  between  digester  oper¬ 
ators  and  the  firemen  in  the  boiler  house.  There  should  be  a 
system  of  signals,  or  a  telephone,  so  that  at  least  an  hour  before 
the  digester  valve  is  expected  to  be  opened  the  firemen  may  be 
warned  to  be  ready  for  the  excessive  pull  on  their  plant.  In  this 
way  such  times  can  be  passed  without  any  unusual  condition. 

When  slack  coal  could  be  placed  in  the  stoker  hoppers  for 
about  a  dollar  per  ton,  there  certainly  was  not  much  incentive 
to  work  out  and  maintain  more  efficient  methods  of  combustion, 
and  as  a  matter  of  fact  in  many  cases  the  expense  involved  in 
obtaining  better  results  was  not  justified  by  the  saving  produced. 

But  that  condition  does  not  obtain  now.  The  present  price 
of  fuel  will  justify  the  expenditure  of  money  for  better  furnaces 
and  the  various  instruments  that  are  necessary  to  obtain  and  main¬ 
tain  proper  combustion.  That  the  consumer  is  wide  awake  to 
the  necessity  of  economy  in  the  use  of  fuel  is  evidenced  by  the 
unprecedented  demand  for  boiler  and  furnace  instruments. 

It  is  here  that  a  warning  should  be  sounded.  The  writer 
has  seen  many  cases  where  a  plant  has  been  equipped  with  ex¬ 
pensive  indicating  and  recording  instruments  and  then  left  alone 
with  the  idea  that  somehow  the  instruments  would  automatically 


THE  POWER  PLANT 


415 


secure  the  desired  results.  The  object  here  is  to  call  attention 
to  the  wrong  use  made  of,  and  the  wrong  impressions  that  may 
be  gained  from  the  carbon  dioxide  (CO2)  recorder.^ 

Although  this  instrument  still  leaves  something  to  be  desired 
in  its  construction  and  operation,  it  is  highly  enough  developed 
to  be  of  very  great  value  in  obtaining  proper  combustion,  but, 
in  the  majority  of  cases,  the  instrument  is  installed  and  the  fire¬ 
man  is  told  to  maintain  a  certain  percentage  of  CO2  in  the  escap¬ 
ing  gases.  He  soon  learns  that  if  he  has  a  deep  fuel  bed  and  a 
small  amount  of  air  a  high  CO2  reading  will  result,  but  what  he 
does  not  know  is  that  such  a  condition  is  also  a  good  one  for 
the  production  of  CO  and  that  a  high  percentage  of  CO2  in  the 
flue  gases  very  often  means  a  high  percentage  of  CO. 

Thus -the  record  from  the  CO2  recorder  may  show  that  very 
good  results  have  been  obtained,  whereas  just  the  opposite  may 
be  true  and  large  quantities  of  fuel  in  the  form  of  incompletely, 
consumed  carbon  have  passed  out  with  the  products  of  com¬ 
bustion.  There  are  conditions  that  will  produce  CO  other  than 
the  one  just  mentioned.  It  should  be  kept  in  mind  that  the 
kindling  temperature  of  CO  is  rather  high,  about  1200  deg.  F., 
so  that  if  there  is  not  a  thorough  mixing  of  air  and  fuel  before 
coming  in  contact  with  the  comparatively  cool  heating  surfaces 
incomplete  combustion  will  result. 

It  is  vitally  important  that  the  results  from  the  CO2  re¬ 
corder  be  checked  frequently  by  making  a  complete  gas  analysis 
with  the  Orsat  apparatus.  This  checking  with  the  Orsat  serves 
two  purposes ;  first,  it  shows  whether  or  not  the  recorder  needs 
adjustment,,  and  second,  if  there  is  any  CO  present. 

There  is  a  tendency  to  surround  the  Orsat  apparatus  with 
a  great  deal  of  mystery  and  to  create  the  impression  that  its  use 
is  limited  to  technically  trained  men.  This  attitude  is  particular¬ 
ly  unfortunate,  for  there  is  not  an  engineer  worthy  of  the  name 
that  cannot  master  the  use  of  the  Orsat  apparatus  in  two  hours  or 
less.  Such  a  man  has  been  setting  valves  and  determining 
^  the  horse  power  of  reciprocating  steam  engines  by  means  of  the 
steam  engine  indicator  for  years,  and  there  is  no  doubt  that  the 
Orsat  is  easier  to  use  and  the  results  more  easily  analyzed.  A 
knowledge  of  chemistry  is  not  necessary.  The  chemicals  or 
solutions  can  be  secured  from  any  dealer  in  chemical  reagents. 

The  Use  of  the  Orsat. 

The  burette  a  is  graduated  in  cubic  centimeters  up  to  100, 
and  is  surrounded  by  a  water  jacket  to  prevent  any  change  in 
temperature  from  affecting  the  volume  of  the  gas  during  analysis. 

For  accurate  work  it  is  advisable  to  use  four  pipettes,  b,  c, 
d,  e,  the  first  containing  a  solution  of  caustic  potash  for  absorb- 

*  For  descriptions  of  the  various  types  of  CO2  records,  see  “Finding  and 
Stopping  Waste  in  Modern  Boiler  Rooms,”  Vol.  II,  pages  151  to  156.  Harrison 
Safety  Boiler  Works. 


4i6  modern  pulp  AND  PAPER  MAKING 

ing  carbon  dioxide,  the  second  an  alkaline  solution  of  pyrogallol 
for  absorbing  oxygen,  and  4;he  remaining  two  an  acid  solution 
of  cuprous  chloride  for  absorbing  carbon  monoxide.  Each 
pipette  contains  a  number  of  glass  tubes,  to  which  some  of  the 
solution  clings,  thus  facilitating  absorption.  In  pipettes  d  and  e 
these  tubes  contain  copper  wire  to  strengthen  the  cuprous  chlo¬ 
ride  solution  as  its  absorbent  power  becomes  weakened.  The 
rear  half  of  each  pipette  is  fitted  with  a  rubber  bag,  one  of  which 


Fig-  155- — Diagram  of  Orsat  apparatus  for  testing  flue  gases,  (a) 
Burette;  (b)  caustic  potash  pipette;  (c)  alkaline  pyrogallol  pipette; 
(d,  e)  cuprous  chloride  pipettes;  (f)  levelling  bottle;  (g)  3-way 
cook;  (h)  U-tube;  (i)  cock;  (j)  rubber  bag;  (k)  tube. 

is  shown  at  j,  to  protect  the  solution  from  the  action  of  the  air. 
The  solution  in  each  pipette  should  be  drawn  up  to  the  mark  on 
the  capillary  tube. 

The  gas  is  drawn  into  the  burette  through  the  U  tube  h, 
which  is  filled  with  spun  glass,  or  similar  material,  to  clean  the 
gas.  To  discharge  any  air  or  gas  in  the  apparatus,  the  cock  g 
is  opened  to  the  air  and  the  bottle  f  is  raised  until  the  water 
in  the  burette  reaches  the  lOO-cubic  centimeter  mark.  The 
cock  g  is  then  turned  so  as  to  close  the  air  opening  and  allow 
gas  to  be  drawn  through  h,  the  bottle  f  being  lowered  for  this 


THE  POWER  PLANT 


417 


purpose.  The  gas  is  drawn  into  the  burette  to  a  point  below  the 
zero  mark,  the  cock  g  then  being  opened  to  the  air  and  the 
excess  gas  expelled  until  the  level  of  the  water  in  f  and  in  a  are 
at  the  zero  mark.  This  procedure  is  necessary  in  order  to  obtain 
the  zero  reading  at  atmospheric  pressure. 

The  apparatus  as  well  as  all  connections  leading  thereto  should 
be  carefully  tested  for  leakage.  Simple  tests  can  be  made.  For 
example,  if  after  the  cock  g  is  closed  the  bottle  f  is  placed  on 
top  of  the  frame  for  a  short  time  and  again  brought  to  the  zero 
mark,  the  level  of  the  water  in  a  is  above  zero  mark,  a  leak  is 
indicated. 

Before  taking  a  final  sample  for  analysis,  the  burette  a  should 
be  filled  with  gas  and  emptied  once  or  twice,  to  make  sure  that 
all  the  apparatus  is  filled  with  new  gas.  The  cock  g  is  then  closed, 
the  cock  i  opened,  and  the  gas  driven  over  into  b  by  raising  f. 
The  gas  is  drawn  back  into  a  by  lowering  f  and  when  the  solu¬ 
tion  in  b  has  reached  the  mark  in  the  capillary  tube,  tbe  cock  i  is 
closed  and  a  reading  is  taken  on  the  burette,  the  level  of  the 
water  in  the  bottle  f  being  brought  to  the  same  level  as  the 
water  in  a.  The  operation  is  repeated  until  a  constant  reading 
is  obtained,  the  decrease  in  volume,  in  cubic  centimeters,  being 
the  percentage  of  COg,  in  the  flue  gases. 

The  gas  is  then  driven  over  into  the  pipette  c  and  the  appa¬ 
ratus  manipulated  in  a  similar  manner.  The  difference  between 
the  resulting  reading  and  the  carbon  dioxide  reading  gives  the  per¬ 
centage  of  oxygen  in  the  flue  gases. 

The  next  operation  is  to  drive  the  gas  into  the  pipette  d, 
the  gas  being  given  a  final  wash  in  e,  and  then  passed  into  the 
pipette  c  to  absorb  any  hydrochlorid  acid  fumes  that  may  have 
been  given  off  by  the  cuprous  chloride  solution,  if  old ;  such 
fumes  would  increase  the  volume  of  the  gases  and  make  the 
reading  on  the  burette  less  than  the  true  amount. 

The  sum  of  the  percentages  by  volume  of  CO2,  O,  and  CO 
is  subtracted  from  100  and  for  practical  purposes  this  difference 
is  taken  as  the  percentage  by  volume  of  N. 

The  gas  must  be  passed  through  the  burettes  in  the  order 
named,  as  the  pyrogallol  solution  will  absorb  carbon  dioxide  and 
the  cuprous  chloride  solution  will  absorb  oxygen. 

As  the  gases  in  the  flue  are  under  less  than  atmospheric  pres¬ 
sure,  they  will  not  of  themselves  flow  through  the  pipe  connect¬ 
ing  the  flue  to  the  apparatus.  The  gas  may  be  drawn  into  the 
pipe  in  the  way  already  described,  but  this  is  tedious.  A  rubber 
bulb  aspirator  connected  to  the  air  outlet  of  the  cock  g  will 
quickly  draw  a  new  supply  of  gas  into  the  pipe.  Another  form  of 
aspirator  draws  the  gas  from  the  flue  in  a  constant  stream,  thus 
insuring  a  fresh  supply  for  each  sample. 

The  analysis  made  by  the  Orsat  apparatus  is  volumetric ;  if 
the  analysis  by  weight  is  required,  it  can  be  found  from  the  volu¬ 
metric  analysis  as  follows : 


4i8  modern  pulp  AND  PAPER  MAKING 

Multiply  the  percentages  by  volume  by  the  molecular  weight 
of  each  gas,  and  divide  the  products  by  the  sum  of  all  the  prod¬ 
ucts  ;  the  quotients  will  be  the  percentages  by  weight.  For  most 

w(^k  the  use  of  the  oven  values  of  the  molecular  weights  insures 
sufficient  accuracy. 

The^  even  values  of  the  molecular  weights  of  the  gases  that 
appear  in  an  analysis  by  an  Orsat  are : 


Carbon  dioxide  (CO2) . 44 

Carbon  monoxide  (CO) .  28 

Oxygen  (©2) .  32 

Nitrogen  (N2) .  28 


The  following  table  indicates  the  method  of  converting  a 
volumetric  flue-gas  analysis  into  an  analysis  by  weight. 

Conversion  of  a  flue-gas  analysis  by  volume  to  one  by  weight : 


CONVERSION  OF  A  FLUE-GAS  ANALYSIS  BY  VOLUME  TO  ONE  BY  WEIGHT 


Gas 

Analysis 
by  volume 
(per  cent) 

Molecular 

Weight 

Volume 

times 

molecular 

weight 

Analysis 
by  weight 
(per  cent) 

Carbon  dioxide  (CO2). . . 

12,2 

12  -f  (2x  16) 

536.8 

536  8  ^ 

3022.8 

Carbon  monoxide  (CO) _ 

.4 

12  +  16 

11.2 

11.2 

3022.8 

Oxygen  (O2) . 

6  9 

2  X  16 

220.8 

220.8 

3022.8 

Nitrogen  (N2) . 

80.5 

2  X  14 

2254.0 

2254.0  ,,  „ 

3022.8 

Total . 

100.0 

3022 . 8 

100. 0i 

Frorn  the  flue-gas  analysis  the  weight  of  air  actually  used  for 
combustion  can  be  computed  from  this  formula  provided  the 
percentage  by  weight  of  C  in  the  fuel  is  known: 


Weight  of  air  =  3 . 036  ( - - |  vr 

\C0i  +  CO/ 

Where  N,  CO2  and  CO  are  percentages  by  volume  in  the  flue 
gas  and  C  is  the  percentage  by  weight  of  carbon  in  the  fuel. 

The  quantity  of  heat  (B.  t.  u.)  lost  in  the  flue  gases  per 

pound  of  fuel  is  L=o.24  W(T _ t). 

Where  JF=:weight  in  pounds  of  flue  gases  per  pound  of  dry 
fuel. 

r=temperature  of  flue  gases,  °F. 

/^temperature  of  atmosphere,  °F. 

0-24=:specific  heat  of  flue  gases. 


419 


THE  POWER  PLANT 

The  weight  W  of  the  flue  gases  per  pound  of  dry  fuel  is  com¬ 
puted  from  the  analysis  by  the  formula: 

/  11  CO2  +  8O  +  7  (CO  +  N)\ 

^  V  3  (CO2  +  CO)  / 

where  CO2,  O,  CO,  and  N  are  the  percentages  by  volume,  by  an¬ 
alyses  of  the  flue  gas.  C  is  the  percentage  by  weight  of  the  car¬ 
bon  in  the  dry  fuel.  ,  r  r  1  t,  j 

The  quantity  heat  (B.  t.  u.)  lost  per  pound  of  fuel  burned 

through  incomplete  combustion  of  carbon  and  the  presence  of  CO 
in  the  flue  gas  is  in  B.  t.  u.  obtained  by  using  the  formula: 

X  (co+°co,.)  = 

where  CO  and  CO2  are  the  percentages  of  the  gasp  by  volume  in  ^ 
the  flue  gases  and  C  is  the  percentage  of  C  by  weight  in  the  fuel.' 

Design  of  Steam  Plants  for  Pulp  and  Paper  Mills. 

In  considering  the  design  of  a  steam  plant  as  applied  to  the 
paper  industry,  consideration  should  be  given  to  the  following 
main  headings. 

Logical  fuel  to  burn. 

Various  kinds  of  boilers. 

Various  types  of  stokers  or  grates. 

Kinds  and  types  of  auxiliary  equipment  for  the  boiler  house. 
Fans  and  engines  for  producing  draft. 

Soot  blowers. 

Boiler  feed  regulators. 

Balanced  draft. 

Gauges  and  gauge  boards. 

Distribution  of  steam  throughout  the  plant. 

Types  of  steam  units  used  for  driving  the  paper  machines. 
Heating  system  for  the  mill. 

Reclamation  of  heat  units. 

Logical  Fuel  to  Burn. 

While  it  is  conceded  that  the  use  of  anthracite  and  bitumi¬ 
nous  coal  predominates  in  most  industries  in  this  country  and 
the  paper  industry  is  no  exception — the  exact  type  of  fuel  used 
must  be  determined  by  the  general  location  of  the  plant,  freight 
rates,  freight  facilities,  flexibility  of  coal  deliveries,  nearness  to 
mine’s  and  large  coaling  stations,  nearness  to  supplies  of  oil  or 
other  fuel,  tank  steamer  facilities,  etc. 

In  addition  to  coal  natural  gas  is  used  as  fuel  in  the  paper 
industry  in  some  instances  (chiefly  in  the  yirginias)  and  crude 
oil  is  used  in  mills  on  the  Pacific  Coast  and  in  some  Maine  mills. 
Coal:  A  pulp  and  paper  mill  engineer  should  secure  govern- 


420  MODERN  PULP  AND  PAPER  MAKING 

ment  and  other  publications  describing  the  coal  from  different 
seams.  If  not  competent  to  judge  himself,  he  should  avail  him¬ 
self  of  the  services  of  a  combustion  engineer  in  selecting  his  coal 
and  drawing  up  specifications  for  it.  All  coal  should  be  bought 
on  specification  based  on  sampling,  testing  and  chemical  analysis. 
The  Keystone  Consolidated  Publishing  Company  of  Pittsburgh 
get  out  a  Coal  Catalog  which  contains  all  the  necessary  informa¬ 
tion  and  should  be  in  the  hands  of  every  large  user  of  coal.  The 
U.  S.  Bureau  of  Mines  will  also  supply  literature  on  this  subject. 

Until  quite  recently  the  different  grades  of  anthracite  were 
burned  in  the  paper  industry  with  induced  draft,  i.  e.,  either  with 
natural  draft  produced  by  chimneys  or  by  fans.  Then  followed  a 
combination  of  induced  and  forced  draft.  Hand  fired  installa¬ 
tions  used  approximately  >4  inch  to  ij4  inch  of  draft  in  the  pit. 
Hand  firing,  with  various  types  of  grates,  and  with  an  air  space 
of  approximately  9  to  ii  per  cent,  was  fairly  satisfactory  and  in 
many  cases  really  economical,  at  least  at  pre-war  prices  for  an¬ 
thracite  coal.  However,  it  had  its  limitations,  and  a  steaming 
capacity  of  from  20  to  30  per  cent  and  many  times  as  much 
power,  could  be  obtained  from  bituminous,  with  more  modern 
firing  equipment. 

The  large  percentage  of  ash,  and  the  consequent  increase  in 
coal  required  to  equal  bituminous  steaming,  makes  the  labor 
cost  of  the  hand  fired  operations  approximately  twice  as  high  as 
with  an  automatic  stoking  installation. 

However,  offhand  we  would  state  that  it  does  not  pay  to 
seriously  consider  the  installation  of  stokers  m  anv  pulp  or  paper 
mill  unit  that  does  not  exceed  1,000  or  1,500  H.  'P. 

Oil:  According  to  government  statistics  165,000,000  barrels 
of  fuel  oil  were  used  in  1917  in  the  United  States.  Oil  has  the 
advantage  of  simplifying  firing,  high  evaporation,  high  capacity 
per  square  foot  of  grate  surface  or  radiating  surface,  lessened 
abor  cost,  cleanliness,  flexibility,  i.  e.,  ability  to  change  quickly 
to  maximum  or  minimum  supply  of  steam.  On  the  other  hand, 
we  believe  that  the  impingement  of  the  flames  on  the  tubes  neces¬ 
sitates  a  lot  of  tube  renewals.  In  some  localities  fuel  oil  is  the 
logical  fuel,  but  with  the  increase  in  the  price  of  fuel  oil  since 
the  war,  its  disadvantages  have  been  given  more  consideration, 
and  It  IS  not  in  so  much  favor  as  in  pre-war  times.  Full  infor¬ 
mation  about  every  detail  of  the  use  of  fuel  oil  in  power  plants 
IS  given  in  the  copiously  illustrated  booklet  entitled  “Efficiency  in 
^e  Use  of  Oil  Fuel,”  published  by  the  U.  S.  Bureau  of  Mines. 

le  author  of  this  booklet  is  J.  M.  Wadsworth  and  it  can  be 
Obtained  by  sending  15  cents  to  the  Superintendent  of  Docu¬ 
ments  Government  Printing  Office,  Washington.  Anyone  think¬ 
ing  of  using  oil  fuel  will  find  everything  they  need  to  know  in 
this  handbook. 

hatural  Gas:  Of  this  fuel  we  cannot  speak  from  personal 
experience,  never  having  operated  plants  with  this  fuel.  We  un- 


THE  POWER  PLANT 


421 


derstand,  however,  that  its  advantages  are  high  steaming  ca¬ 
pacity,  flexibility,  reduction  in  labor  cost,  cleanliness,  compact-  • 
ness,  and  (in  certain  localities)  cheapness. 

Stokers. 

There  are  a  number  of  excellent  stokers  on  the  market  and 
we  would  not  have  any  reader  infer  that  the  particular  ones 


Fig.  156. — Typical  installation  of  Coxe  stoker  under  horizontal  water 

tube  (Edgemoor)  boiler. 


we  have  happened  to  illustrate  here  are,  in  our  opinion,  the 
only  ones  to  use  in  pulp  and  paper  mills. 

The  main  thing  is,  apart  from  mechanical  efficiency  in  the 


422 


MODERN  PULP  AND  PAPER  MAKING 


stoker  itself,  that  the  stoker  installation  should  have  a  high  re¬ 
serve  capacity  (several  per  cent  over-rating  frequently  being 
required)  because  sometimes,  owing  to  two  or  more  digesters 
being  blown  in  at  about  the  same  time,  wash-ups  on  the  paper 
machine,  etc.,  sudden  very  large  demands  for  steam  are  made. 
This  possibility  of  sudden,  irregular,  excessive  demands  for 
steam  is  the  principal  unique  factor  in  power  plant  design  for 
the  pulp  and  paper  industry. 


Courtesy:  Combustion  Engineering  Corpn.,  New  York. 


Fig-  157-  Installation  of  six  Coxe  stokers  under  250  H.P.  boilers. 


The  stokers  which  we  have  illustrated  we  consider  excellent 
examples  of  efficient  modern  stokers  that  have  proved  their  value 
in  hundieds  of  installations.  However,  we  have  selected  them  to 
illustrate  simply  because  the  illustrations  were  available.  In  ad¬ 
dition  to  the  Taylor  and  the  Coxe,  there  are  the  Babcock  & 
Wilcox,  Westinghouse,  Jones  Underfeed,  Harrington,  Green, 
Files,  LaClede-Christy,  and  many  other  good  makes. 

To  sum  up:  no  matter  what  the  type  of  stoker,  have  plenty 
of  draft.  In  the  case  of  forced-draft  installations  have  a  good, 
genercms  force  draft  fan,  preferably  two  units  of  sufficient  size  to 
furnish  the  required  draft  in  the  pit  (zero  to  at  least  6  inches) 
without  the  fan  engine  speed  exceeding  50  to  150  r.  p.  m.  The 
fan  engine  to  be  enclosed,  preferably  horizontal  with  forced  feed 
lubrication  for  both  engine  and  cylinder  oil. 

A  good  stoker  should  be  scientifically  planned  to  utilize  the 


THE  POWER  PLANT 


423 


peculiarities  of  bituminous  or  semi-bituminous  coal,  or  of  mix¬ 
tures  of  such  coal  with  limited  amounts  of  anthracite  steam  sizes. 
It  is  not  merely  a  device  for  feeding  coal;  rather,  it  is  a  com¬ 
plete  system  of  combustion,  comprising  means  for  feeding  the 
coal  in  quantities  as  needed,  supplying  air  in  proportionate 
amounts,  causing  the  air  and  distilled  gases  to  mix  and  burn 
without  smoke,  burning  the  solid  fuel  (coke),  discharging  the 
ashes. 


Courtesy:  American  Engineering  Co.,  Philadelphia,  Pa. 

Fig.  158. — Taylor  stoker  with  power  dump. 


1.  Retort. 

2.  Hopper. 

3.  Tuyere  Box. 

4.  Tuyeres. 

5.  Feeding  Ram. 

6.  Distributing  Rams. 

7.  Extension  Grate. 

8.  Dump  Plate. 

9.  Pawls,  supporting  Dump 

Plate. 

10.  Steam  Cylinder  of  Pow¬ 

er  Dump. 

11.  Damper  controlling 

draft  to  extension 
grate. 


12.  Hand  Wheel  control¬ 

ling  damper  No.  ii. 

13.  Air  Duct  fan  draft. 

14.  Dampers  in  air  duct. 

15.  Handle  controlling 

dampers  No.  14. 

16.  Sprocket  Chain  Driv¬ 

ing  Worm  gear  No. 
17. 

17.  Worm  and  Gear  driv¬ 

ing  stoker. 

18.  Connecting  Rod. 

19.  Link  forming  fulcrum 

for  lever  by  which 
motion  is  imparted 


to  rams,  6,  6,  and 
extension  grate. 

20.  Link  by  which  exten¬ 

sion  grate  is  reci¬ 
procated  to  prevent 
clinkers  from  adher¬ 
ing. 

21.  Spacing  Washers  by 

which  lengths  of 
stroke  of  rams  6,  6, 
and  link  20  are  de¬ 
termined. 


All  these  processes  are  carried  out  with  a  high  degree  of 
precision  by  mechanical  means,  and  with  minimum  dependence 
on  the  human  element. 

Specifically,  the  following  results  should  be  accomplished : 

(i)  Coal-burning  capacity,  and  therefore  steaming  capacity 
should  be  enormously  increased.  Continuous  operation  at  from 
200  to  300  per  cent  of  rating  is  often  secured,  according  to  the 
boiler  design  and  the  coal  used.  Operation  at  even  higher  rates 


424 


MODERN  PULP  AND  PAPER  MAKING 


is  possible.  Note:  A  “boiler  horsepower”  is  equivalent  to  34.5 
pounds  of  water  per  hour  evaporated  into  steam  at  212°  Fahr. 
and  atmospheric  pressure.  In  an  actual  boiler  the  water  starts 
at  less  than  that  temperature,  is  evaporated  into  steam  at  a  higher 
temperature  and  pressure,  and  is  probably  superheated  also. 
Hence,  the  weight  of  water  per  horsepower  actually  evaporated  is 


Fig.  159. — Installation  of  Combustion  Engineering  Corporation’s  type  E 
stoker  under  upright  water  tube  (Stirling)  boiler. 


less  than  34.5  pounds,  to  allow  for  the  heat  added  before  and 
after  evaporation. 

Water-tube  boilers  are  generally  rated  at  one  boiler  horse¬ 
power  for  every  ten  square  feet  of  heating  surface.  “Operation 
at  normal  rating”  means  that  for  every  square  foot  of  heating 
surface  the  boiler  is  evaporating  3.45  pounds  of  water  per  hour 
“from  and  at”  212°  Fahr.,  or  its  equivalent  for  the  actual  con¬ 
ditions. 

“Operation  at  200  per  cent  of  rating”  means  that  the  boiler 
is  evaporating  double  the  rated  quantity  of  water  per  hour.  It 
does  not  imply  higher  steam  pressure. 


THE  POWER  PLANT  425 

A  hand-fired  boiler  will  deliver  only  its  normal  rating  or  a 
little  more,  and  its  efficiency  falls  very  rapidly  as  the  output  is 
forced. 

(2)  A  saving  in  fuel  is  effected  of  from  10  to  20  per  cent 
for  equal  steam  output,  as  compared  with  hand  firing  at  normal 
rating,  assuming  that  the  same  degree  of  intelligence  is  exercised 
as  would  be  the  case  with  high-class  hand  firing. 

(3)  Response  to  varying  loads  should  be  almost  immediate. 
With  good  stokers  it  is  unnecessary  to  incur  the  stand-by 


Courtesy:  Combustion  Engineering  Corpn.,  New  York. 

Fig.  160. — Two  type  E  stokers  installed  in  boiler  room  of  a  paper  mill. 
Nominal  rating  of  boilers  219  H.P.  each. 

losses  of  many  banked  boilers  held  in  readiness  for  a  sudden 
demand. 

(4)  Smoke  is  greatly  reduced  or  wholly  eliminated. 

(5)  By  proper  adjustment  of  feed  and  draft,  varying  grades 
of  fuel  are  successfully  burned. 

(6)  Repair  expenses  should  be  nominal. 

(7)  Labor  expense  is  minimized.  With  fuel  of  average 
quality,  one  operator  can  look  after  12  to  15  modern  stokers  of 
ordinary  size,  representing  10,000  rated  boiler  horse-power.  (The 
above  exclusive  of  ordinary  boiler-house  labor  such  as  laborers, 
ash-handers,  chartmen,  foremen,  etc.) 

Stoker  Engines:  These  should  be  of  a  modern  enclosed  type 


Courtesy:  Mechanicville  Specialty  Supply  Mfg.  Co.,  Mechanicville,  N.  Y. 

Fig.  i6i. — J.R.S.  low  and  high  grade  coal  burner  in  position  under  boiler. 

grades  of  coal,  down  to  and  including  anthracite  screenings  dust, 
also  buckwheat,  coke  breeze,  etc. 

It  consists  of  filler  plates  covering  the  entire  fire  box  area,  all 
free  air  being  sealed  from  entering  through  the  ash  pit.  The 
plates  are  so  arranged  that  draft  delivered  under  pressure  up¬ 
ward  into  the  fire  box  is  returned  downward  in  a  lateral  flow 
that  distributes  the  oxygen  through  the  fuel  so  perfectly  and 
steadily  that  all  heat  units  ordinarily  passing  off  in  the  form 
of  gas  and  smoke  are  entirely  consumed.  It  tends  to  correct 
faulty  chimney  drafts  and  variations  in  chamber  size.  It  can 
be  placed  in  any  type  of  furnace  and  used  in  connection  with 
either  mechanical  or  hand  stoking.  The  draft  is  applied  auto- 


426  MODERN  PULP  AND  PAPER  MAKING 


and  should  be  approximately  to  3^  larger  than  ordinarily 
recommended  by  the  makers  themselves. 


Smith  Force  Draft  Equipment. 


In  addition  to  stokers,  we  have  found  very  useful  the  Smith 
Force  Draft  Equipment.  The  installation  of  this  appliance  adds 
much  to  the  flexibility  of  the  plant,  enabling  it  to  burn  various 


THE  POWER  PLANT  427 

matically  and  can  be  quickly  set  to  handle  minimum  require¬ 
ments  or  peak  loads.  It  is  claimed  by  the  makers  that  this  device 


Courtesy:  Mechanicville  Specialty  Supply  Mfg.  Co.,  Mechanicville,  N.  Y. 

Fig.  162.  Front  elevation  of  J.R.S.  burner  showing  circulation  of  air 

under  pressure. 


will  show  material  savings  in  cost  of  operation,  and  our  own 
experience  all  tends  to  confirm  this,  especially  in  case  of  low 
grade  fuel. 

Boilers. 

The  type  of  boiler  to  be  used  depends  largely  on  the  size  of 
the  plant.  Arguments  can  be  found  for  both  Return  Tubular 
and  Water  Tube  boilers.  Water  Tube  boilers  have  undoubted 
advantages,  but  where  the  size  of  the  plant  is  small  (mills  up 
to  and  including  40  tons)  Return  Tubular  might  well  be  consid¬ 
ered.  For  larger  plants  install  ordinarily  good  Water  Tube 
boilers,  having  in  either  case  one  boiler  in  excess  of  normal 
requirements  to  take  care  of  increased  loads  due  to  variations 
in  weight,  steam  requirements  in  winter  months,  repairs,  etc. 

Babcock  &  Wilcox  in  “Steam:  Its  Generation  and  Use,” 
which  they  supply  free  to  boilers  users,  outline  the  advantages 
of  Water  Tube  boilers  in  general.  Those  we  consider  most  im¬ 
portant  are,  quick  steaming,  greater  safety  and  easy  access  for 
repairs.  For  details  as  to  all  the  best  makes  of  both  types  of 
boiler  consult  “Condensed  Catalogues  of  Mechanical  Equip¬ 
ment,”  published  by  the  American  Society  of  Mechanical  Engi¬ 
neers  and  “Sweet’s  Engineering  Catalogue.”  These  are  both 
well-known  publications,  free  to  people  seriously  interested,  and 
give  pictures  and  descriptions  of  all  the  best  makes  of  boilers  and 
boiler  room  equipment. 

In  a  mull  having  four  13-ton  digesters,  and  manufacturing 
approximately  125  tons  sulphite  and  80  tons  paper,  boilers  were 
installed  as  per  the  table  on  following  page. 

In  sulphite  mills  suitable  provision  should  be  made  for  burn¬ 
ing  refuse.  Eor  such  work  combination  forced  and  induced  draft 
is  preferable.  For  a  furnace  of  approximately  8  ft.  x  7  ft.  size, 
grates  of  Herringbone  type  are  very  satisfactory,  embodying 
quick  dumping  features,  making  it  possible  to  burn  down  the 


428  MODERN  PULP  AND  PAPER  MAKING 


TABLE  OF  STOKER  AND  BOILER  CAPACITY  IN  STEAM  PLANTS  OF  FOUR 

TYPICAL  MILLS 


Mill 

Capac¬ 

ity 

(Tons) 

No.  of 
Machines 

No.  of 
Digesters 

No.  of 
Boilers 

How 

Fired 

Fuel 

Used 

Percentage 
of  Rating 
Operated 

H.P. 
per  Ton 
Product 

Grate  Area 
per  Ton 
Product 
(sq.  ft.) 

Paper. .  . 

Sulphite 

50 

50 

2 

2 

(13-ton) 

4 

Under¬ 

feed 

Stoker 

Bit.  Coal 

137 

14.2 

2.7 

Paper. .  . 

Sulphite 

80 

125 

2 

4 

(13-ton) 

8 

Overfeed 

Stoker 

Bit.  Coal 

120 

11.7 

1.6 

Paper. . . 

40 

1 

(large) 

4 

Hand 

20%  Bit. 
80%  Anth. 

100 

18 

4 

Paper. . . 

45 

2 

(small) 

6 

Hand 

20%  Bit. 
80%  Anth. 

100 

25 

7.3 

refuse  quick,  before  the  brick-work  would  become  cooled  down. 
In  such  a  case  approximately  i.i  square  feet  of  grate  surface  and 
45  cubic  feet  furnace  capacity  should  be  provided  for  each  ton 
of  sulphite  made. 

This  is  in  case  the  wood  is  prepared  with  a  barking  drum. 
The  power  capable  of  being  generated  from  refuse  from  a  bark¬ 
ing  drum,  in  which  125  cords  of  green  wood  is  being  barked, 
is  equal  to  approximately  200  H.  P.  per  hour  for  20  hours. 

TABLE  OF  APPROXIMATE  CUBICAL  CAPACITY  OF  BOILER  ROOM,  COAL  BUNKER 
SPACE,  ETC.,  REQUIRED  PER  TON  OF  PAPER  IN  MANUFACTURE  OF  GRADES  RUN¬ 
NING  FROM  100%  SULPHITE  TO  100%  KRAFT  SHEET— WEIGHT  FROM  .30  TO 
50  LB.  BASIS. 


Cu.  Ft. 

Boiler  Room 

Cu.  Ft. 

Bunker  Space 

Sq.  Ft. 

Floor  Space 

Sq.  Ft. 
Heating  Area 

Sq.  Ft. 

Economizer  Surface 

2588 

240 

96 

296 

148 

Note.  These  figures  can  be  safely  used  for  manufacturing  of  most  papers  from  sulphite. 


THE  POWER  PLANT 


429 

In  considering  the  available  power  from  refuse  made  in  pre¬ 
paring  wood  with  disc  barkers,  it  is  safe  to  assume  that  62 
boiler  H.  P.  can  be  obtained  from  every  cord  of  wood  prepared. 

Ordinarily  a  13-ton  digester  will  require  a  minimum  of 
300  H.  P.  at  the  time  of  steaming,  a  maximum  at  the  time 
of  starting  (about  2^  hours  after  steaming)  of  700  and  an 
average  of  550  H,  P.  per  hour  for  the  period  covering  a  9-hour 
cook. 

As  before  mentioned,  the  personnel  of  the  plant  has  a  large 
bearing  on  the  boiler  capacity  necessary  to  operate  a  pulp  mill, 
especially  a  sulphite  mill.  For  example,  in  a  mill  operating  two 
13-ton  digesters,  cooking  50  tons  of  high-grade  unbleached  stock, 
there  will  be  from  WA  to  5  cooks  per  24  hours.  It  will  be  obvious 
that  the  efficiency  of  the  operation,  viz. :  the  reclamation  of  the 
acid,  the  making  of  the  acid,  and  the  general  efficient  operation 
of  the  plant  will  be  dependent  on  the  proper  timing  of  the  cook¬ 
ing  operation.  If  the  digesters  are  bunched  in  such  a  50-ton 
sulphite  mill,  it  is  possible  to  pull  on  the  boiler  house  to  the 
extent  of  1,200  horsepower.  On  the  other  hand  with  propei* 
spacing  of  the  cooking  operation,  the  maximum  horsepower 
might  well  be  in  the  neighborhood  of  850  H.  P. 

Anyone  with  any  practical  experience  in  making  pulp  will 
recognize  that  it  is  impossible  at  all  times  to  space  the  digesters 
perfectly,  because,  owing  to  the  various  contingencies,  such  as 
steam  and  water  conditions,  blow  pit  conditions,  screening,  etc., 
it  will  often  be  necessary  to  bunch  the  digesters.  It  is  for  this 
reason  that  in  designing  boiler  installations  for  sulphite  mills, 
generous  provision  must  be  made  for  taking  care  of  just  such 
unavoidable  contingencies. 

TABLE  GIVING  SIZE  AND  TYPE  OF  BOILERS  IN  TWO  TYPICAL  MILLS  AND  ONE  WITH 
TWO  13-TON  DIGESTERS  AND  ONE  WITH  FOUR  13-TON  DIGESTERS 


.  Nominal  Per  cent  of 

No.  Digesters  No.  Boilers  Capacity  Type  How  Fired  Rating  Operated 


2  2  1740  Water  Tube  Stoker  137% 

4  4  1200  “  “  “  120% 

Auxiliary  Equipment  for  Boiler  Use. 

We  consider  this  one  of  the  most  important  items  in  the 
proper  design  of  a  power  plant  for  a  pulp  and  paper  mill.  The 
most  important  point  to  be  considered  under  this  heading  is  boiler 
feed  apparatus  with  which  to  supply  raw  water  for  boiler  pur¬ 
poses.  We  have  found  that  beyond  a  possibility  of  a  doubt,  it 
pays  well  to  have  at  least  three  independent  means  by  which  to 
supply  the  water  to  the  heaters  and  the  boiler  feed  pumps. 

Provision  should  be  made  so  that  the  water  can  be  by-passed 


430 


MODERN  PULP  AND  PAPER  MAKING 


Fig.  163. — Typical  pressure  chart  for  power  plant  of  mill  making  sulphite 

and  paper. 


Fig.  164. — Typical  flow  meter  chart  for  power  plant  of  mill  making 

sulphite  and  paper. 


THE  POWER  PLANT 


431 


from  the  heater  direct  to  the  suction  of  the  pumps.  For  instance, 
one  might  provide  an  emergency^  connection  direct  from  the 
underwriter  pump,  whether  it  be  duplex  or  turbine  type.  More¬ 
over,  there  should  be  two’ different  sources  of  supply,  one  elec¬ 
trically  driven  and  one  steam  driven  for  water  for  the  heaters 
proper.  The  water  should  in  all  cases  be  filtered  and  if  necessary 
softened  so  as  to  be  free  from  ingredients  tending  to  form  scale. 
This  subject  has  already  been  dealt  with  in  Chapter  XV,  under 

the  heading  “Water  Supply.”  r  r  ,• 

With  specific  reference  to  the  various  methods  for  feeding 
boilers,  there  is  first  the  old  stand-by,  the  individual  large  inspira¬ 
tor  or  injector.  For  pulp  and  paper  mill  work  of  any  size  this 
equipment  is  practically  obsolete,  although  there  are  instances 
where  its  utilization  for  emergencies  has  proved  to  be  a  good 
investment.  M!ore  to  be  recommended  are  the  usual  single  and 
duplex  plunger  pumps  and  direct  connected  turbo  units.  The 
writer  has  found  a  unit  embodying  a  turbine  direct  connected  to 
a  four-stage  centrifugal  pump  entirely  satisfactory  for  this 
service.  However,  numerous  manufacturers,  both  of  turbines 
and  pumps,  are  capable  of  supplying  excellent  equipment  for» 

this  purpose.  ^  •  1  .  -i  vu 

We  will  not  attempt  in  this  chapter  to  deal  m  detail  with 

figures  on  the  proper  amount  of  power  which  should  be  utilized 
for  auxiliary  boiler  room  equipment  under  various  conditions. 
Such  information  can  be  found  in  the  various  standard  text  books 
on  steam  engineering.  In  considering  pulp  and  paper  mills,  it  is 
almost  immaterial  what  type  of  auxiliary  units  are  used  provided 
that  the  capacity  is  sufficient  and  that  proper  provision  is  made 
for  the  utilization  of  the  excess  exhaust. 

To  return  to  the  question  of  boiler  feed  pumps,  there  is  one 
important  fact  on  which  we  can  hardly  lay  too  much  emphasis. 
While  the  turbine  pumps  are  very  desirable,  under  no  con¬ 
sideration  should  any  pulp  and  paper  plant  be  operated  without 
one  good,  big,  generous,  modern,  duplex  or  triplex  pump  of  sub¬ 
stantial  design  in  the  boiler  room.  ,  •  n  •  r 

We  would  consider  the  following  an  ideal  installation  tor  a 

50-ton  sulphite  mill  and  50-ton  paper  mill;  (i)  One 
driven  triplex  pump,  size  8  x  10,  200  g.p.m.  capacity.  (2)  One 
steam  driven  duplex  outside-pack  plunger  pump,  200  g.  p.  m 
capacity.  (3)  One  direct  connected  turbine  driven  centrifugal 
pump  of  200  g.  p.  m.  capacity.  (Note  :  This  type  preferable  when 
accurate  Venturi  meter  readings  are  required.)  The  valves  m 
the  plunger  pump  should  be  of  good  quality  composition  backed 

by  some  stiff  metal.  ^  •  u  xj 

Ideal  specification  for  the  turbine  driven  pump ;  4-inch 
izontal  two-stage  split  case,  centrifugal  pump,  equipped  wit 
bronze  impellors,  bronze  covered  steel  shaft,  and  having  an  ex 
tended  base  and  flexible  coupling  direct  to  40  H.  P.  steam  tur¬ 
bine.  Pump  to  have  a  capacity  of  300  g.p.m.  against  a  pressure 


432  MODERN  PULP  AND  PAPER  MAKING 

of  175  lbs.  Efficiency  55  per  cent.  Steam  turbine  to  be  of  single 
stage,  horizontal  type. 

All  units  when  possible  should  be  properly  regulated  on  the 
basis  of  steam  pressure  and  the  pressure  on  the  boiler  feed  line. 

When  figuring  capacities  for  boiler  feed  pumps,  particularly 
of  duplex  type,  first  see  to  it  that  at  least  sufficient  head  is  pro^ 
vided  for  hot  water  purposes,  to  maintain  a  pressure  of  at  least 
9  pounds  (this  pressure  contingent  on  the  temperature  of  the 
water  being  purnped)  on  the  suction  proper,  figuring  normal 
rating  of  the  boilers.  In  fact  if  the  actual  boiler  horsepower 
readings  are  available,  take  actual  and  add  one-half  to  the 
theoretical,  and  you  will  then  have  what  we  have  found  from 
experience  to  be  a  good  boiler  pump  installation. 

Under  no  consideration  would  we  consider  a  piston  speed 
much  to  exceed  40  ft.  per  min.  In  the  event  of  other  units  which 
might  be  well  considered  as  auxiliary  equipment  such  as  the 
vai  ions  draft  generating  apparatus,  be  this  induced  or  forced,  we 
have  found  that  the  manufacturers’  suggestions  as  to  sizes  best 
be  multiplied  by  approximately  50  per  cent.  This  is  based  on 
actual  experience  in  operation.  The  average  engineer  figuring 
on  this^  work  does  not  anticipate  some  of  the  dangerous  con¬ 
tingencies  that  arise. 

We  will  cite  one  example — bunching  of  digesters;  perhaps 
the  steaming  of  two  or  three  beaters  simultaneously,  the  starting 
of  two  machines  in  unison.  With  the  above,  while  pulling  the 
normal  rating  of  say  100  horsepower,  the  mill  will  sometime?  pull 
as  high  as  from  1,200  to  1,500  horsepower,  particularly  during 
the  starting  up  of  the  machines  or  in  the  event  of  their  pulling  a 
full  iy2  inch  to  2^  inch  steam  supply,  when  the  paper  is  running’ 
wet,  etc.,  etc. 

Soot  Blo'wers. 

The  author  is  decidedly  of  the  opinion  that  soot  blowers  are 
a  g^ood  investment  and  add  materially  to  the  efficiency  of  modern 
boilers.  However,  a  soot  blower,  to  be  a  profitable  investment, 
should  be  used  in  an  intelligent  manner.  The  blowing  should 
be  done  several  tiines  a  day  because  when  soot  and  ash  first 
collect  on  the  tubes  it  is  easier  to  remove,  whereas,  if  it  is  allowed 
to  remain,  the  heat  will  fuse  it  into  a  hard  substance  which  can 
only  be  removed  by  scraping.  There  are  a  number  of  excellent 
soot  blowers  on  the  market,  any  of  which  will  soon  pay  for  them¬ 
selves  by  the  savings  effected. 

Boiler  Feed  Regulator. 

These  are  sometimes  called  feed  water  regulators.  Many 
engineers  do  not  favor  the  installation  of  these  regulators.  It  is 
our  experience,  however,  that  they  are  a  good  investment.'  They 
tend  to  decrease  the  variation  of  pressure  when  the  load  on  the 


THE  POWER  PLANT 


433 


boilers  is  heavy,  as  well  as  presenting  certain  other  advantages. 

Although  these  devices  differ  in  construction,  they  are  all 
designed  to  accomplish  the  same  results  and  the  following  de¬ 
scription  of  the  work  accomplished  by  the  Copes  regulator  could 
well  apply  to  any  of  the  reliable  makes  of  feed  water  regulator. 

The  regulator  feeds  continuously  as  long  as  there  is  a  load 
on  the  boiler.  On  heavy  loads  it  automatically  drops  the  water 
level  so  as  to  increase  the  steaming  capacity.  On  light  loads  it 
automatically  raises  the  water  level,  and  saves  the  furnace  heat 
which  would  otherwise  be  wasted.  On  steady  loads,  it  main¬ 
tains  a  constant  water  level. 

The  governor  maintains  a  fixed  excess  in  the  feed  line  above 
boiler  pressure.  As  the  pressure  varies,  the  feed  pressure  varies 
correspondingly.  The  same  governor,  with  a  charge  in  con¬ 
nections,  will  give  a  fixed  constant  pressure. 

Balanced  Draft. 

Balanced  Draft  is  obtained  by  the  automatic  regulation  of 
both  the  supply  of  air  to  the  furnace  and  the  escape  of  the  gases 
from  the  furnace  in  such  manner  as  to  maintain  at  all  times  a 
constant  predetermined  draft  in  the  furnace  for  all  rates  of 
combustion. 

Its  principle  is  to  supply  all  the  air  needed  for  perfect  com¬ 
bustion  but  no  more,  and  at  the  same  time  maintain  as  little 
suction  in  the  furnace  as  possible  and  still  have  sufficient  draft  to 
take  away  the  gases  from  the  furnace  chamber  as  rapidly  as  they 
are  formed. 

These  requirements  are  independent  functions.  They  must  be 
controlled  separately  and  independently  if  the  best  results  are 
to  be  obtained. 

Balanced  Draft  control  of  the  air  supply  meets  the  first  re¬ 
quirements  perfectly.  By  its  use,  any  required  amount  of  air 
can  be  forced  through  fuel  beds  of  any  thickness  or  density, 
thus  maintaining  whatever  rate  of  combustion  may  be  desired. 

Balanced  Draft  control  of  the  flue  damper  meets  the  second 
requirement  as  the  flue  damper  is  kept  constantly  in  its  correct 
position  by  automatic  opening  and  closing,  thus  keeping  the  re¬ 
moval  of  the  waste  gases  under  perfect  control. 

Pressure  in  the  combustion  chamber  tends  to  rise  when  either 
the  air  pressure  increases  or  the  flue  damper  closes,  or  when  the 
two  act  simultaneously.  It  falls  when  the  air  pressure  decreases 
or  the  flue  damper  opens,  or  both  act  simultaneously.  If  both 
are  controlled  automatically,  it  is  apparent  that  any  desired  pres¬ 
sure  can  be  obtained  in  the  furnace  chamber  under  all  conditions. 

Atmospheric  pressure  or  slightly  less  than  atmospheric  is  found 
to  be  the  most  economical  in  a  great  majority  of  furnaces.  At 
this  pressure,  whether  in  hand-fired  plants  or  where  stokers  are 
installed  there  is  no  inrush  of  air  above  the  fuel  bed  from  open 
fire  doors,  through  cracks  or  pores  of  boiler  settings,  through  ob- 


434  MODERN  PULP  AND  PAPER  MAKING 

\ 

servation  doors,  or  through  other  openings  of  whatever  kind. 
The  amount  of  air  passing  through  the  fuel  bed  is  also  restricted 
to  the  amount  required  for  perfect  combustion.  The  excess  air 
admitted  to  the  furnace,  therefore,  is  reduced  to  the  minimum. 

Since  air  is  not  drawn  in  above  the  fire,  when  Balanced  Draft 
is  installed,  the  hot  gases  are  not  diluted.  The  initial  tempera¬ 
ture  is  greater  for  this  reason,  and  the  percentage  of  CO2  in  the 
flue  gases  is  higher. 

Heat  absorption  by  the  boiler  is  proportional  to  the  difference 
between  the  temperature  of  its  heating  surface  and  that  of  the 
gases.  The  temperature  of  the  furnace  gases  above  that  of  the 
boiler  heating  surface  is  maximum  when  Balanced  Draft  is 
installed.  Therefore,  the  absorption  of  heat  by  the  boiler  is 
maximum  under  these  conditions. 

With  the  quantity  of  air  passing  through  the  fire  reduced  to 
the  minimum  necessary  for  perfect  combustion,  the  resulting  vol¬ 
ume  of  gases  above  the  fire  is  also  the  minimum  and  the  velocity 
of  their  passage  through  and  out  of  the  boiler  setting  is  cor¬ 
respondingly  reduced.  These  intensely  hot  gases,  therefore,  have 
ample  time  to  transmit  their  heat  to  the  boiler. 

The  inevitable  result  is  increased  evaporation  per  pound  of 
coal  and  per  square  foot  of  heating  surface.  Furthermore,  be¬ 
cause  the  gases  in  the  furnace  chamber  are  held  back,  they  diffuse 
and  penetrate  to  the  most  remote  parts  of  the  heating  space, 
coming  into  contact  with  every  square  inch  of  heating  surface. 

By  the  use  of  Balanced  Draft  on  boilers  formerly  operating  on 
natural  draft,  250  per  cent  increase  in  capacity  is  frequently  ob¬ 
tained  without  the  slightest  decrease  in  efficiency.  This  feature 
is  of  particular  value  when  peak  loads  have  gone  beyond  the 
capacity  of  the  power  plant.  In  a  plant  where  several  boilers 
have  ordinarily  been  in  use,  it  is  possible  to  take  one  out  of  con¬ 
tinuous  service  for  reserve. 

The  results  are  brought  about  by  the  obvious  possibility  of 
increasing  boiler  capacity  economically  by  increasing  the  rate  of 
combustion.  Greater  economy  in  normal  operation  is  also  se¬ 
cured  by  burning  a  reduced  amount  of  coal  to  develop  the  same 
power.  How  so  radical  an  improvement  can  be  effected  is  ap¬ 
parent  from  the  fact  that  Balanced  Draft  combustion  produces 
intensely  hot  gases  and  improves  the  transmission  of  heat  from 
gas  to  boiler  by  increasing  (i)  the  area  of  contact  and  (2)  the 
period  of  their  application  diffusion  of  the  gases  over  the  heating 
surfaces. 

With  the  volume  of  chimney  gases  reduced  by  the  elimina¬ 
tion  of  excess  air,  the  stack  is  required  to  remove  only  the  gases 
of  combustion.  Being  also  relieved  of  the  burden  of  pulling 
air  through  the  fuel  bed,  its  effective  capacity  is  increased  to 
such  an  extent  that  additional  boilers  may  be  attached  to  a  chim¬ 
ney  which  formerly  was  overloaded.  The  troublesome  back 
pressure  on  the  last  of  a  line  of  boilers  operated  on  ordinary 


THE  POWER  PLANT  435 

forced  draft  and  connected  to  an  overload  stack,  is  relieved  by 
Balanced  Draft. 

Whenever  furnace  doors  in  hand-fired  boilers  are  opened, 
large  volumes  of  cold  air  rush  in.  This  occurs  also  in  stoker- 
fired  boilers  through  openings  for  inspection  of  the  fires  and 
for  the  removal  of  clinker  and  ash.  The  cold  air,  striking  the 
highly  heated  tubes  of  the  boiler  and  the  interior  of  the  setting, 
chills  them  suddenly  and  causes  rapid  contraction.  When  the 
opening  is  closed,  the  quick  rise  in  temperature  causes  equally 
rapid  expansion.  There  can  be  but  one  result  from  such  vio¬ 
lent  alternation  of  contraction  and  expansion — leaky  tubes, 
cracked  boiler  setting  and  linings. 

Balanced  Draft  eliminates  the  objectional  conditions  just  de¬ 
scribed,  with  the  result  that  the  life  of  a  boiler  and  its  setting 
is  greatly  prolonged  and  repairs  radically  reduced.  The  de¬ 
creased  maintenance  cost  is  not  only  the  advantage  as  avoiding 
the  inconvenience  of  having  boilers  out  of  service  for  repairs  is 
a  very  important  consideration. 

Practical  economy  naturally  demands  that  one  fireman  in  a 
plant  attend  to  as  many  boilers  as  possible.  With  the  fireman’s 
mind  relieved  of  all  care  of  the  draft,  he  is  able  to  give  undivided 
attention  to  his  other  duties  and  so  extend  the  range  of  his  service. 
This  is  particularly  desirable  in  stoker-fired  plants. 

Then,  too.  Balanced  Draft  is  an  assurance  that  the  highest 
furnace  efficiency  will  be  maintained  day  in  and  day  out,  under  all 
conditions  of  load  and  weather,  even  by  an  unskilled  fireman,  at 
the  same  time  effecting  very  gratifying  savings  in  fuel  cost.  _ 

Since  it  is  not  always  possible  to  hire  and  keep  intelligent 
and  conscientious  firemen  this  is  a  very  important  consideration. 

A  very  large  saving  by  the  use  of  Balanced  Draft  is  very 
generally  effected  by  changing  from  a  high  grade,  expensive 
fuel,  to  a  low  grade,  cheaper  one.  Frequently  a  local  coal  can 
be  substituted  for  one  brought  from  distant  mines  at  high  freight 
rates,  and  burned  with  equally  good  or  better  results.  Surpris¬ 
ingly  good  results  can  sometimes  be  obtained  by  mixing  anthra¬ 
cite  and  bituminous  coal. 

As  the  principle  of  Balanced  Draft  relates  to  perfect  combus¬ 
tion  irrespective  of  method  of  fuel  supj)ly,  it  applies  to  all  hand- 
fired  furnaces,  to  those  mechanical  stokers  which  are  already  or 
which  can  be  fitted  with  pressure  air  supply,  and  to  furnaces  using 
hard  or  soft  coal,  oil  or  blast  furnace  gas.  The  method  of  appli¬ 
cation  is  similar  in  all  cases,  requiring  only  slight  modification 
to  suit  individual  cases. 

Gauges. 

There  is  no  appliance  which,  in  our  opinion,  will  pay  as  good 
returns  upon  the  investment,  as  a  modern  segregated  control  and 
gauge  board.  Such  a  board  should  contain,  ( i )  master  gauge. 


436  MODERN  PULP  AND  PAPER  MAKING 

(2)  gauges  for  recording  feed  water  temperature,  (3)  indicating 
and  recording  flue  temperature  pyrometers  for  each  boiler,  (4) 
recording  draft  gauge,  (5)  individual  steam  meters  for  each 
boiler,  (6)  U  gauges  and  balanced  draft  gauges  for  each  unit, 
(7)  instrument  for  recording  time  and  length  of  time  at  which 
the  flues  were  blown,  (8)  instrument  for  recording  time  and 
length  of  time  at  which  boilers  were  blown,  (9)  instrument  for 


165.— Gauge  Board  recently  installed  in  large  plant  manufacturing 
sulphite  pulp  and  paper.  In  the  center  of  the  board,  projecting  above 
the  top,  is  the  master  steam  gauge.  Immediately  beneath  this  is  a 
G.  S.  Witham,  Jr.,  draft  fan  engine  regulator.  To  the  left  of  the 
master  gauge  are  respectively,  in  the  order  named,  the  flue  gas  tem¬ 
perature  recorder,  draft  pressure  recording  gauge,  and  feed  water 
temperature  recording  gauge.  To  the  right  of  the  master  gauge  are 
instruments  for  recording  the  temperature  of  feed  water  into  and 
out  of  the  economizer.  In  the  center  of  the  board  beneath  the 
Witham  regulator,  is  the  indicating  pyrometer  and  immediately  to 
to  the  left  and  right  of  this  are  steam  flow  meters  (one  of  these  yet  to 
be  installed).  Under  the  row  of  steam  flow  meters  is  a  row  of 
balanced  draft  gauges.  At  the  extreme  right  hand  lower  corner  of 
the  board  is  the  CO2  recorder.  To  the  left  of  the  board,  standing 
on  the  floor  is  the  Venturi  meter. 

recording  time  and  length  of  time  at  which  safety  valves  were 
blown,  (10)  Venturi  meter  for  indicating  volume  of  water  fur- 
nished^  to  boilers  (various  types  of  flow  meter  can  be  substituted 
for  this),  (ii)  CO2  recorder  of  any  good  make. 

The  Venturi  meter  reading  together  with  the  steam  output 
reading  and  a  number  of  pounds  of  coal  burned  makes  it  possible 
to  calculate  very  accurately  the  general  efficiency  of  the  boiler 
installation. 

Steam  Pressures. 

It  is  not  our  intention  to  enter  into  detail  regarding  steam 
pressures.  We  will  simply  state  that  it  is  pretty  generally  con- 


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THE  POWER  PLANT 


437 


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438  MODERN  PULP  AND  PAPER  MAKING 

ceded  that  150  to  175  pounds  pressure  is  pretty  good  practice  in 
pulp  and  paper  mill  work.  Whether  or  not  you  are  operating 
a  steam  turbine  and  generating  your  own  power  has  a  bearing 
on  the  seam  pressure  and  degree  of  superheat.  Some  arguments 
have  been  advanced  in  favor  of  the  utilization  of  superheated 
steam  for  cooking  pulp  and  for  paper  making.  The  author’s  ex¬ 
perience  about  cooking  with  superheated  steam  is  limited,  and  in 
general,  we  are  not  in  favor  of  so  doing.  Neither  do  we  favor 
the  utilizing  of  superheated  steam  for  operating  paper  mill  en¬ 
gines  and  for  drying  paper.  We  have  found  it  very  unsatisfac¬ 
tory.  Saturated  steam,  after  passing  through  the  engines,  gives 
up  its  heat  much  more  readily,  increases  the  drying  capacity  of 
the  machine  and  gives  a  more  uniform  sheet  of  paper.  More¬ 
over,  our  experience  tends  to  show  that  the  use  of  saturated 
steam  gives  a  little  stronger  sheet  of  paper. 

Distribution  of  Steam  Through  the  Plant. 

Considerations  as  to  different  kinds  of  pipe,  types  of  flanges, 
gaskets,  drip  systems,  etc.,  are  ordinarily  taken  care  of  by  the 
designing  engineer.  We  will  not  attempt  to  enter  into  details  on 


this  subject  in  this  book.  A  great  deal  of  data  relative  to  such 
installations,  the  proper  sizes,  velocities,  etc.,  can  be  obtained  from 
standard  text  books  and  engineers’  hand  books. 


THE  POWER  PLANT 


439 


After  operating  several  different  kinds  and  types  of  plants, 
however,  we  are  frank  to  admit  that  there  are  two  respective 
types  of  steam  mains  which  we  favor.  The  first  is  the  Holly  Drip 
System  which  calls  for  good  generous  receiver  separators  at  the 
engine  proper.  The  second  system  which  we  favor  is  a  modern 
drip  system  embodying  drip  connections  opposite  each  boiler  con¬ 
nection.  In  other  words,  a  substantial  drip  connection  on  the 
bottom  of  all  tees  in  the  boiler  house  proper,  this  running  to  a 
receiver  and  the  utilization  of  one  trap,  this  connecting  to  the 
hot  well.  Further,  a  generous  size  of  drip  connection  on  all 


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Ortnt/er  Room 


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C  ~  Sealer  Room 
D'Ro/fi  Storage  Room 

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Fig.  i68. 


mains  throughout  the  plant,  same  being  piped  to  the  receiver,  and 
the  employment  of  a  drip  from  which  the  trap  discharges  to  the 
hot  well. 

Closed  Loop  Trap  Systems:  The  point  emphasized  by  the 
enclosed  trap  system  people  is  substantially  that  latent  heat  is 
lost  when  condensation  is  returned  to  an  open  heater.  On  careful 
examination,  however,  of  heat  reclaiming  systems,  such  as  we 
will  show  later,  it  will  be  appreciated  that  it  is  much  better  to  seg¬ 
regate  the  waste  heat  units,  convert  these  into  hot  water  and  in 
turn  use  this  hot  water  as  a  substitute  for  live  steam.  In  this 
event  the  alleged  loss  will  be  materially  reduced  primarily  because 
the  feed  water  temperature  of  the  hot  water  in  question  will  be 
kept  below  the  flash  point  and  not  lost  to  the  atmosphere. 


440 


MODERN  PULP  AND  PAPER  MAKING 


The  following  is  a  description  of  one  of  the  best  known  closed 
loop  boiler  feeding  systems.  This  is  the  Farnsworth  system 
which  calls  for  a  special  type  of  boiler  feeder  and  a  special  type 
of  condensation  pump,  both  designed  by  the  Farnsworth  Com¬ 
pany  and  both,  in  the  writer’s  opinion,  highly  efficient. 

Figure  170  shows  the  Farnsworth  system  applied  to  a  paper 
machine  having  a  basement  underneath  it.  This  system  is  ex¬ 
plained  as  follows : 

The  paper  machine  is  divided  into  two  sections,  one  of  these 
sections  to  have  75  per  cent  of  the  dryers  and  the  other  section 


Fig.  169. 


the  remaining  25  per  cent.  The  steam  and  return  headers  be¬ 
tween  the  two  sections  are  cut,  and  a  steam  separator  is  placed 
on  the  end  of  the  return  header  for  the  dry  end  section  which 
separates  the  condensation  from  the  steam  which  has  blown  out 
into  this  portion  of  the  return  header.  This  steam  is  passed  over 
to  supply  the  steam  header  for  the  remaining  dryers  on  the  wet 
end.  On  the  end  of  the  return  header  for  the  wet  end  dryers  is 
placed  a  duplex  condensation  pump,  condenser  vacuum  ty[)e. 
This  machine  has  cold  water  sprays  in  the  top  of  the  tank.  The 
spray  water  condenses  the  vapors  in  the  return  line  producing  a 
forced  steam  circulation. 

In  other  words  exhaust  steam  enters  the  dry  end  of  the  paper 
machine  and  passes  through  the  dryers  on  the  dry  end  at  a  high 


441 


Fig.  170. — Farnsworth  system  applied  to  a  paper  machine  having  a  basement  underneath  it. 


MODERN  PULP  AND  PAPER  MAKING 


442 

velocity  due  to  the  condensing  of  the  steam  in  the  wet  end  section 
assisted  by  the  vacuum  produced  by  the  condensing  sprays  in  the 
duplex  condensation  pump  on  the  end  of  the  return  line  for  the 
wet  end  section.  This  also  produces  a  high  velocity  of  steam 
through  the  wet  end  section  with  the  result  that  water  and  air  is 
eliminated  from  both  sections  and  ,a  constant,  even,  known  tem¬ 
perature  at  all  times  is  produced. 

The  dryers  on  the  dry  end  are  hottest  with  a  gradual  de¬ 
crease  in  temperature  as  the  wet  end  is  approached. 

If  for  any  reason  insufficient  steam  should  pass  through  the 
steam  separator  to  maintain  the  required  pressure  in  the  wet 
end  section  steam  is  by-passed  through  a  reducing  valve  and 
the  proper  amount  is  supplied. 

Summing  up,  therefore,  the  steam  supply  line  for  the  paper 
machine  is  connected  at  or  near  the  beginning  of  the  dry  end. 
Steam  is  allowed  to  blow  through  all  the  dryers  in  the  dry  end 
section  and  out  into  the  return  line  carrying  with  it  all  the  water 
and  air  in  these  dryers.  These  dryers  are,  therefore,  nothing 
more  than  the  steam  supply  line  for  the  dryers  on  the  wet  end. 

The  condensation  is  then  separated  from  the  steam  that  has 
blown  through,  and  this  steam  is  passed  over  to  supply  the  dryers 
on  the  wet  end  section.  The  condensation  that  collects  in  the 
separator  is  drained  into  a  simplex  condensation  pump.  The 
air  which  enters  the  receiving  chamber  of  each  machine  escapes 
through  the  vent. 

In  the  closed  loop  boiler  feeding  system  the  condensation 
which  is  collected  in  the  simplex  condensation  pump  and  in 
the  duplex  condensation  pump,  condenser  vacuum  type,  is 
pumped  automatically  during  the  operation  of  the  machine  to 
the  receiving  chamber  of  the  duplex  boiler  feeder  located  from 
3  to  10  feet  above  the  high  water  line  of  the  boilers. 

The  duplex  boiler  feeder  has  two  chambers — one  of  which 
is  always  receiving  while  the  other  is  delivering  the  condensation 
with  all  its  latent  heat  directly  into  the  boilers  giving  a  high  feed 
water  temperature  and  saving  anywhere  from  10  to  30  per  cent 
of  the  coal.  The  duplex  boiler  feeder  and  the  condensation 
pumps  require  only  one-tenth  to  one-fourth  the  amount  of  steam 
used  by  the  common  pump  because  in  these  machines  steam  is 
applied  directly  in  the  surface  of  the  water  instead  of  behind  a 
piston. 

The  condensation  from  all  high  pressure  traps  is  discharged 
directly  into  the  line  leading  to  the  receiving  chamber  of  the  du¬ 
plex  boiler  feeder.  The  condensation  from  all  low  pressure 
heating  systems,  fan  coils,  etc.,  is;  drained  into  simplex  or 
duplex  condensation  pumps  and  is  forced  up  to  the  receiving 
chamber  of  the  duplex  boiler  feeder  by  the  application  of  live 
steam  on  the  surface  of  the  condensate  in  the  tank  while  it  is 
in  the  receiving  position. 

The  Closed  Loop  Boiler  Feeding  system  is  a  very  efficient 


THE  POWER  PLANT 


443 


method  for  handling  condensation  because  the  pressure  is  never 
relieved  from  the  surface  which  would  lower  the  temperature 
to  correspond  with  the  decreased  pressure. 

Figure  171  shows  the  systems  applied  to  a  board  mill  using 
live  steam  in  the  dry  end  containing  one-third  of  the  total  number 
of  dryers ;  the  remainder  of  the  dryers  are  supplied  with  exhaust 
steam.  In  this  case  the  machines  which  drain  the  paper  machine 
are  set  in  pits,  there  being  no  basement  underneath  the  paper 
machine. 

Under  these  conditions  the  live  steam  division  of  the  paper 
machine  and  the  exhaust  steam  division  are  each  divided  as  in 
the  case  of  Figure  170.  That  is  to  say,  each  division  is  subdivided 
into  two  sections,  one  section  to  have  75  per  cent  of  the  dryers, 
and  the  remaining  section  25  per  cent. 

With  this  arrangement  live  steam  blows  through  the  first  sec¬ 
tion  on  the  dry  end  and  out  into  the  return  line  at  a  high  velocity. 
It  passes  through  a  steam  separator  and  over  into  the  second 
section  of  the  dry  end  where  it  is  condensed,  and  this  condensing 
effect,  assisted  by  the  simplex  condensation  pump,  condenser 
vacuum  type,  on  the  end  of  the  return  line  produces  a  forced 
steam  circulation  system  through  both  sections. 

The  exhaust  steam  division  of  this  paper  machine  is  handled 
exactly  as  described  for  Figure  170.  ^ 

The  dryers  on  the  dry  end  are  hottest  with  a  gradual  decrease 
in  temperature  as  the  wet  end  is  approached.  The  hot  dryers  on 
the  dry  end  set  the  paper  as  it  leaves  the  machine.  The  condensa¬ 
tion  which  is  drained  into  the  separator  on  the  live  steam  dryers 
is  forced  to  the  receiving  chamber  of  the  duplex  boiler  feeder 
by  the  pressure  carried  on  the  dryers. 

The  other  three  machines  pump  the  condensate  to  the  receiv¬ 
ing  chamber  of  the  duplex  boiler  feeder,  and,  as  previously 
stated,  all  the  condensation  with  its  valuable  heat  units  is  de¬ 
livered  directly  into  the  boilers. 

One  of  the  main  points  we  want  to  warn  against  in  laying 
out  steam  mains  for  a  plant  is  to  have  any  kind  of  installation 
that  will  make  it  out  of  the  question  to  make  repairs  in  each 
division  without  shutting  off  the  complete  main.  The  shutting  off 
of  a  complete  main  will  frequently  do  more  harm,  even  if  only 
done  once  a  year,  than  operating  the  plant  under  constant  heavy 
steam  pressure  for  several  years.  Reliable  shut-off  valves  should 
be  provided  for  each  department,  making  it  possible  to  repair 
various  units  without  allowing  the  mains  to  become  cooled. 

In  addition  to  the  above,  we  have  found  that  more  damage  has 
been  done  to  steam  mains,  and  more  leaks  have  been  caused, 
by  improper  dripping  than  from  any  one  other  cause.  It  is  a 
very  easy  item  to  so  pitch  the  pipe,  and  to  so  provide  separators, 
that  all  wet  steam  is  taken  care  of  when  the  plant  is  operating 
week  days.  But  the  important  item — the  neglect  of  which  has 
(as  we  have  often  seen)  spoiled  otherwise  excellent  plants — is  to 


444 


i 


Fig.  171.— Farnsworth  system  applied  to  a  board  mill. 


THE  POWER  PLANT  445 

make  provision  for  the  elimination  of  water  pockets  and  to  pro¬ 
vide  at  least  some  current  through  the  steam  mains  on  Sundays. 

We  have  seen  steam  plants  leaking  in  hundreds  of  places 
owing  to  the  fact  that  the  plant  is  shut  down  dead  on  Sunday,  the 
management  depending  on  the  mains  tightening  up  on  Monday. 
It  can  readily  be  seen  that,  after  the  pipes  have  been  filled  with 
water,  which  causes  a  tremendous  strain,  and  after  the  joints 


Pipe  Covering. 

Few  items  in  power  plant  design  are  more  important  than 
good  pipe  covering.  We  will  not  dwell  on  this  subject  here  be¬ 
cause  excellent  information  can  be  obtained  free  from  the  Mag¬ 
nesia  Association  of  America,  Philadelphia,  who'  have  gone  to 
great  expense  to  work  out  specifications  covering  all  the  uses  of 
the  products  sold  by  the  companies  belonging  to  the  association. 
Every  operating  engineer  should  have  this  literature,  which  will 
be  sent  free  to  any  person  interested.  It  will  enable  the  calcu¬ 
lation  of  just  the  right  thickness  of  covering  for  any  pipe  line. 

In  general  we  mjght  state,  however,  that  any  pulp  and  paper 
rnill  superintendent  who  has  not  given  serious,  careful  and  scien¬ 
tific  consideration  to  proper  pipe  covering  is  simply  throwing 
away  money  in  an  inexcusable  manner. 


446  MODERN  PULP  AND  PAPER  MAKING 

\ 

% 

Types  of  Units  for  Driving  Paper  Machines. 

There  are  various  types  of  units  used  for  driving  paper 
machines  and  these  are  used  in  several  different  combinations  and 
connected  in  different  ways  to  the  steam  system.  It  is  easier  to 
make  this  clear  by  drawings  than  by  verbal  explanation,  and  we 
have  prepared  a  number  of  drawings  which,  we  hope,  will  be  clear 
without  detailed  explanation. 


In  general,  there  are  the  following  systems : — Direct  drive 
from  water  wheels  (Fig.  172)  ;  Slow  speed  Corliss  engines, 
belted  direct  to  the  line  shaft  (Figs.  173  and  174)  ;  High  speed 
turbine  units,  driving  through  belts  (Fig.  175)  1  High  speed 
turbines  with  speed  reduction  gears. 

There  have  been  recent  important  developments  along  the 
lines  of  electric  drive.  The  earliest  electrical  systems  consisted 
of  constant  speed  motors  with  mechanical  speed  changing  devices, 
similar  to  those  used  when  the  machines  were  steam  driven.  A 
later  development  consisted  of  adjustable  speed  motors. 

All  of  the  above  systems  employed  the  usual  mechanical  fea¬ 
tures  of  paper  machine  drive  (Marshall  system)  consisting  of 
main  line  shaft,  bevel  gears,  cone  pulleys  with  vertical  belt  drives, 
friction  clutches,  etc.  This  has  already  been  touched  on  in  the 
chapter  on  the  machine  room. 


Jkcrc//  Shomna  /vufroff  i/vie  ff  P/iPEff  ATficw/^E 
P/rivEN  Sr  /^NaiE  Type  Tyv/yy  ^ppjpble  Jpeeo 
Stepm  CnaiNE  P/pect  Connected  To  Wppi/ieLE  LmT. 


Tw/n  Var/ab/e  Steo/n  £n^’n9 


Fig.  174. 


Sketch  SHOYy/A/a  fbH/ropiNiEP  Phpep  PMc/hne  /fi/nniHO  /Yews 
Ppiyep  By  Stepm  Tupbine  pup  ffoPE  Pp/ye. 


q 

Tb/rer  Cones 

/  /rb/oe  ^/vVc 

□ 

LJu 

Tirri^  steam  Ti/rtun* 


Fig.  175. 


447 


448  MODERN  PULP  AND  PAPER  MAKING 

The  most  recent  development  consists  of  individual  motors 
for  each  section  of  the  paper  machine,  these  motors  being  regu¬ 
lated  by  electrical  devices.  It  is  claimed  for  this  system  that  the  ' 
special  automatic  regulator  used  will  maintain  each  of  the  motors 
in  its  proper  relation  to  every  other  motor  and  to  the  machine  as 
a  whole.  At  the  present  time  this  system  is  just  making  its  debut 
in  the  paper  industry  and  it  seems  to  be  succeeding.  Such  equip¬ 
ment,  if  perfected,  will  permit  of  higher  speeds  and  will  enable 
paper  machines  to  be  installed  in  much  less  space  (for  instance, 
the  basement  can  be  dispensed  with)  and  will  have  many  other 
advantages. 

A  still  more  recent  development  is  a  system  employing  direct 
connected  individual  steam  turbines  for  each  section  of  the 


TABLE  OF  FRICTION  AND  FULL  LOAD  READINGS  TAKEN  FOR  VARI¬ 
ABLE  SPEED  SHAFTS  DRIVING  A  156-INCH  FOURDRINIER  PAPER 
MACHINE,  60-INCH  CYLINDER  MACHINE  AND  126-INCH  FOUR¬ 
DRINIER. 


Friction  Load  of  156  inches  Fourdrinier  Paper  Machine .  319  H.  P. 

Full  Load  of  156  inches  Fourdrinier  Paper  Machine  when  running 
30  lb.  Manila  Paper — ^Formula  60%  Sulphite,  40%  Ground 
Wood . .  391.92  H.P. 

Power  required  to  drive  Variable  Speed  Shaft  on  156-inch  Four¬ 
drinier  Paper  Machine — All  machines  down .  132.78  H.P. 

H.  P.  per  inch  width  of  156-inch  Fourdrinier  Paper  Machine  when 

running  30  lb.  sheet  60-40  formula . .  2.5  H.  P. 

H.  P.  per  inch  trim  of  156-inch  Fourdrinier  Machine  trimming 

14614  inches . .  ■  2.7  H.  P. 

H.  P.  per  inch  of  paper  on  156-inch  Fourdrinier  Machine  with 

deckle  set  at  152  inches .  2.6  H.  P. 

H.  P.  required  to  drive  126-inch  Fourdrinier  Paper  Machine  112- 
inch  deckle  when  running  on  Envelope  24  x  36  inches — 6314- 
lb.  basis .  237.8  H.P. 

H.  P.  per  inch  width  of  above  machines .  1 .85  H.  I’. 

H.  P.  per  inch  width  of  paper  on  above  machines .  2.12  H.  P. 

H.  P.  required  to  drive  96-inch  Cylinder  Machine  running  with 

84-inch  deckle  on  144-lb.  Bristol  Board . ; .  110.7  H.  P. 

H.  P.  per  inches  width  of  machine  on  above  machines .  1.32  H.  P. 

H.  P.  per  inch  of  Paper  on  above  machines .  1-23  H.  P. 


machine,  these  turbines  being  controlled  and  regulated  by  an 
automatic  device. 

All  these  developments  are  taking  place  because  of  the  con¬ 
stantly  increasing  dissatisfaction  with  the  usual  line  shafts,  gears, 
friction  cones,  etc.,  which,  for  years,  have  been  a  troublesome 
feature  of  the  back  drive  of  paper  machines.  When  high  speeds 
are  encountered,  as  in  modern  newsprint  and  bag  paper  ma¬ 
chines,  great  trouble  is  experienced,  not  met  with  in  the  old  days 
at  lower  speeds. 

Consequently,  there  is  no  doubt  that  the  new  drives  have 
come  to  stay.  They  take  a  long  step  towards  the  complete  elimi¬ 
nation  of  excessive  friction,  vibration,  lubrication,  etc. 


r>» 


bi 

tL| 


449 


/ 


450  MODERN  PULP  AND  PAPER  MAKING 


Fig.  176.— Diagram  showing  application  of  Witham,  Jr.,  heat  reclaiming 

system. 


Distribution  of  Steam  to  the  Paper  Machines. 

This  is  one  of  the  subjects  in  pulp  and  paper  engineering  on 
which  almost  no  two  men  agree.  We  find  many  engineers  of 
acknowledged  ability  absolutely  at  variance  with  one  another  on 
this  subject.  We  have  prepared  some  drawings  illustrating  sys¬ 
tems  which  we  have  found  practical  and  which  we  hope  will  be 
of  service  as  suggestions. 


S/f£Tcff  'SMon/na  ^/rfr/inaeMcnT  or  s-Cpoi.e/TS 

/pSrsTrM  /nsTPiiED  roi/r/i/zs  rpr  /trpT  r/ie 
C>iaer3Tep  yypcN /7- /3  aps/Na. 


Fig,  178. 


451 


Fig.  i8i. 


TyP/C/fL  ffi^TPLL/JTlON  or  /^UTOPf/fTtC  T£MP£R/9Tafr€ 
Control  ^ystcm  roR  Drying  Fprsr  on  Frp£R  Mrch/nc 


ig.  _  182.— There  are  several  types  of  controllers  for  regulating  the  dry¬ 
ing  of  the  paper.  This  subject  has  already  been  discussed  in  the 
c  lapter  on  the  machine  room.  The  above  is  a  type  of  installation 
which  the  writer  has  found  to  be  satisfactory. 


452 


THE  POWER  PLANT 


453 


Heating  System  for  Paper  Mills. 

The  nature  of  the  heating  system  must  vary  in  each  and 
every  mill.  There  are  two  main  methods  in  use  today — the 
direct  radiation  system  and  the  hot  blast  system.  In  plants  of 
any  size  a  combination  of  the  two  is  usually  best.  This  is  espe¬ 
cially  true  of  the  finishing  room  where  generally  a  large  force 
of  both  male  and  female  (nowadays  largely  female)  help  is  re¬ 
quired.  Usually,  however,  the  wood  room,  digester  house,  blow 
pits,  screen  room,  beater  room  and  machine  room  can  be  satis-  . 


factorily  heated  by  the  hot  blast  system.  We  show  two  illustra¬ 
tions  of  systems  we  have  found  useful.  Those  interested  in 
making  a  detailed  study  on  this  subject,  we  would  refer  to  the 
very  complete  manuals  published  by  the  B.  F.  Sturtevant  Co.,  of 
Hyde  Park,  Boston,  Mass.,  and  the  Harrison  Safety  Boiler 
Works  of  Philadelphia,  Pa.  We  understand  that  these  books  are 
sent  free  to  interested  parties,  and  they  are  very  complete — espe¬ 
cially  the  “Exhaust  Steam  Heating  Encyclopedia”  of  the  last 
mentioned  concern. 

Reclamation  of  Heat  Units. 

This  subject  is  so  inextricably  bound  up  with  the  foregoing 
topics — proper  heating  of  pulp  and  paper  mills,  distribution  of 
steam  to  the  paper  machine,  etc.,  that  little  remains  to  be  said. 


454 


MODERN  PULP  AND  PAPER  MAKING 


except  to  point  out  some  of  the  writer’s  opinions  as  to  the  ad¬ 
vantages.  The  numerous  illustrations  present  the  details  of  the 
various  systems  much  better  than  could  any  number  of  pages 
of  text. 

One  of  the  most  recent  developments  in  this  regard  is  the 
reclamation  of  heat  units  from  the  digesters,  as  shown  in  Figure 
178. 

As  an  argument  in  favor  of  careful  working  out  of  the  heat 
reclaiming  system,  we  will  cite  the  case  of  a  plant  formerly  su¬ 


pervised  by  the  writer  which  operated  for  twelve  years  under 
substantially  the  following  conditions: — 

The  plant  produced  50  tons  of  paper,  the  grades  being  bonds, 
Manilas  and  envelope  papers.  There  were  two  beater  machines 
— one  90-inch  cylinder  machine  and  one  126-inch  Fourdrinier 
machine.  The  power  plant  included  5  return  tubular  boilers 
and  the  coal  consumption  averaged  about  80  tons  per  day.  Live 
steam  was  utilized  for  every  beater,  the  size  of  the  steam  lines 
to  the  beaters  being  inches.  There  were  six  i8oo-lb.  beat¬ 
ers.  The  bleaching  equipment  was  capable  of  handling  20  tons 
of  stock  and  the  live  steam  lines  for  the  bleaching  equipment 
ranged  in  size  up  to  and  including  2  inches.  Size  was  made  at 
the  plant,  the  water  being  heated  by  steam.  Color  mixing  was 
done  in  the  beater  room,  the  color  barrels  being  agitated  with 
steam.  In  addition  to  the  above  barrels  all  waters  were  heated 


Fig.  185. — Typical  boiler  room  pressure  chart  before  installing  modern 

equipment  and  methods. 


Fig.  186. — Typical  boiler  room  pressure  chart  after  installing  modern 
equipment  and  methods.  (Note  regularity  of  steam  pressure  line.) 


455 


456  MODERN  PULP  AND  PAPER  MAKING 


TABLE  OF  POWER  REQUIRED  PER  TON  OF  FINISHED  PRODUCT  IN 
MILL  OF  125  TON  SULPHITE  AND  100  TON  OF  PAPER  CAPACITY 


Power  Required  per 


Dept. 

Unit  Power  Required  Cord  of  Wood 

Type 

Wood  Room 
(<  (< 

Jack  Ladder 

40 

H.  P. 

.32 

H.  P. 

Endless  chain  angle  type 

Saw  Feed  Carriage 

25 

(t 

.2 

ft 

Standard  saw  carriage 

it  (( 

Circular  Saw 

50 

tt 

.5 

tt 

60"  Circular  Saw 

.(  (( 

Conveyor 

15 

tt 

.15 

tt 

Endless  Chain  V  Trough 

Gr.  Wood  MU 
(( 

Barker 

15 

H.  P. 

Per  ton  of  Gr.  Wd. 

6  H.  P.  Disc  60"  Barker 

Grinder 

350 

ft 

150 

tt 

3  Pocket  Grinder 

((  it 

Sc!  een 

40 

tt 

4.9 

tt 

Cent  Screen 

u  a 

Wet  Press 

8 

tt 

1 

tt 

Stand.  Felt  Type 

Barking  Drum 

Parking  Drum 

75 

H.  P. 

Per  ton  of  Sulphite 

.37  H.  P.  American  suspended  Type 

Plant 

Barking  Drum 

Conveyor 

30 

tt 

.15 

tt 

Endless  chain  "V”  Type 

Plant 

Wood  Room 
((  <( 

Barker 

15 

(t 

.12 

tt 

trough 

60"  Disc  Barker 

Chipper 

150 

tt 

.75 

tt 

4  Knife  Disc  Chippers  84" 

ft  U 

Crusher 

30 

ft 

.15 

tt 

((  (< 

Chip  Elevator 

15 

ft 

.12 

ft 

Drag  Flight  Type 

ti  ci 

Refiner 

15 

tt 

.12 

ft 

Rotary  Type 

ii  a 

Chip  Elevator 

15 

ft 

.12 

tf 

Belt  Type 

Acid  Pump 

Acid  Pumps 

30 

tf 

.24 

ft 

2"  Cent. 

Digester  Room 

Acid  Pumps 

40 

ft 

.32 

8"  Cent. 

Blow  Pit  Room 

Stock  Pump  to  Riffler 

75 

tf 

.6 

10"  Cent. 

Screen  Room 

Knotter  Screen 

5 

tt 

.04 

tf 

Perforated  Cyl.  Type 

((  a 

Stock  Pump  from  RifBer 

135 

tt 

1.12 

tf 

10"  Cent. 

a  a 

to  Screen 

Stock  Screen 

40 

tt 

.32 

tt 

Cent. 

ti  a 

Tailing  Stock  Screen 

40 

tt 

.32 

tt 

Cent. 

a  t( 

Wet  Press 

8 

ft 

.06 

tt 

Stand.  Felt  Type 

a  it 

Screen  Chest  Agitators 

8 

tf 

.06 

tf 

Paddle  Type 

a  <« 

Screen  Stock  Pump 

15 

tt 

.12 

tt 

6"  Cent. 

a  a 

Screen  Grinder 

75 

ft 

.6 

tt 

Emerson  Plug  Jordan 

a  n 

Screen  Press 

8 

tt 

.Off 

tf 

Stand.  Felt  Type 

Kraft  Shred. 
Plant 

Kraft  Shred. 
Plant 

Kraft  Shred. 

Shredder  and  Pulper 

250 

tf 

2.5 

tt 

Agitator  in  Chest 

30 

ft 

.3 

tf 

Revolv.  Paddle  Type 

Stock  Pump 

40 

ft 

.4 

tt 

8"  Cent. 

Plant 

Paper  Mill 
Beater  Room 

Deckers 

8 

tt 

Per  Ton  of  Paper 

.08  “  Revolv.  Cyl.  Type 

it  i( 

Agitator  in  deckered 

10 

tf 

.1 

ft 

Revolv.  Paddle  Type 

t(  It 

stock  chest 

Stock  Pump  to  Beaters 

20 

tt 

.2 

ft 

Cent. 

t(  tt 

Beater  1500  lb. 

50 

ft 

.5 

ft 

Roll  and  Tub  1500  lb. 

tf  tt 

Agitator  in  Jordan  Chest 

10 

tf 

.1 

tt 

Horizontal  Type  Agit. 

a  tt 

Stock  Pump  to  Jordan 

15 

tt 

.15 

ft 

12  X  12  Trip.  Plunger 

It  tt 

Jordan 

225 

tf 

2.25 

tt 

Wagg  Majestic  Jordan 

Machine  Room 

Agitator  in  Mach.  Chest 

10 

it 

.1 

it 

Horizontal  Type  Agit. 

tt  tt 

Stock  Pump  to  Stuff  Box 

15 

ft 

.15 

tt 

12  X  12  Trip. 

tt  tt 

Stuff  Pump 

30 

if 

.3 

tf 

Cent. 

tt  tt 

Diaphragm  Screen 

7 

ft 

.07 

ft 

Flat  Diap.  Screen 

tt  tt 

Constant  speed  low 

85 

if 

.85 

f  f 

A.  C.  Model 

tt  ft 

Fourdrinier  Paper  Mach. 

450 

if 

4.5 

ft 

4  Cyl.  Angle  Typevar.spd. 

tt  tf 

Reels  and  Winders 

50 

if 

.5 

ft 

Upright  Reels 

tt  tt 

Elevators 

15 

if 

.15 

ft 

Hydraulic 

Note — The  plant  containing  the  equipment  as  shown  on  this  Table  was  of  125  tons  sulphite  ca¬ 
pacity  and  from  80  to  85  tons  of  paper.  This  paper  varied  from  100%  sulphite  to  100%  Kraft  sheets. 

Total  Power  Required  in  Mill  Manufacturing  100  per  cent  sulphite  wrapping  paper  was  3150  H.  P. 
or  63  H.  P.  per  ton  of  paper 


THE  POWER  PLANT  457 

and  prepared  with  soap  by  means  of  live  steam  for  the  washing 
of  felts. 

In  the  above  plant  in  1913  under  the  conditions  described,  the 
coal  consumption  per  ton  of  paper  ranged  from  1100  to  1150 
pounds.  After  the  installation  of  a  few  modern  accessories  and 
the  re-arrangement  of  the  piping  with  the  introduction  of  an  ef¬ 
ficient  reclamation  system,  the  coal  consumption  at  this  plant 
was  brought  down  to  approximately  600  pounds  of  coal  per  ton 
of  paper. 

This  meant  a  reduction  of  approximately  40%  in  the  coal 
consumption  in  the  boiler  room.  It  also  allowed  of  a  reduction 
in  labor  of  one  man  one  each  shift,  or  three  men  from  the  total 
power  plant  crew. 

In  connection  with  this  improvement  it  is  interesting  to  know 
the  difference  m  the  two  steam  pressure  charts  shown  in  figures 
185  and  186. 

Estimate  of  Power  Required  in  Pulp  and  Paper  Mills 

It  is  manifestly  impossible  to  furnish  any  estimate  of  the 
power  required  for  the  manufacture  of  pulp  and  paper  that  will 
cover  all  different  cases,  or  any  particular  case,  by  direct  applica- 
tion. 

The  length  of  conveyors  alone,  which  will  call  for  a  consider¬ 
able  variation  in  power,  will  never  be  the  same  in  any  two  plants. 
The  boiler  horsepower  required  for  the  digesters  will  depend  on 
the  manner  in  which  the  cook  is  conducted  at  any  particular  mill. 
Many  other  factors  will  vary.  However,  the  figures  given  here 
are  based  on  practical  experience  and  care  has  been  taken  to 
mention  what  is  not  included  in  any  of  the  estimates. 

It  is  assumed  that  the  wood  is  received  at  the  mill  in  4-foot 
or  2-foot  lengths  and  that  the  preparation  begins  with  the  removal 
of  the  bark. 

It  is  assumed  that  log  hauls  and  other  conveyors  are  of  aver¬ 
age  length,  not  exceeding  500  feet  in  any  case,  and  of  modern 
construction. 

It  is  also  assumed  that  the  entire  plant  runs  24  hours  per  day, 
except  Sundays,  with  the  exception  of  the  wood  room,  which  is 
assumed  to  run  9  hours  per  day. 

Grinders  are  to  be  driven  by  electric  motors  or  hydraulic  tur¬ 
bines  through  direct  connection.  All  other  equipment,  except 
paper  machines,  is  assumed  to  be  motor  driven,  either  direct  con¬ 
nected  or  otherwise.  Paper  machines  are  assumed  to  be  driven 
by  their  own  separate  engines,  turbines  or  electric  motors. 

It  is  not  necessary  to  add  anything  to  the  figures  given,  as  they 
have  all  been  calculated  very  liberally  so  as  to  be  always  on  tbe 
safe  side.  Allowance  is  made  in  all  cases  for  normal  stoppages, 
but  it  is  assumed  that  all  equipment,  motors,  shafting,  etc.,  is 
maintained  in  normally  perfect  condition  by  competent  mechanics. 


458  MODERN  PULP  AND  PAPER  MAKING 

Thus,  the  estimate  will  furnish  a  skeleton  to  which  individuals 
can  add,  subtract  or  otherwise  adapt,  so  as  to  suit  the  particular 
conditions  with  which  they  are  confronted. 


EQUIPMENT  FOR  A  loo-TON  GROUND  WOOD  MILL 

Number  of  Horsepower  Required 

Min.  Max.  Average 

I  Log  Haul .  8  20  15 

I  Gang  Saw  (1-60"  saw  slashing  4'  wood)  8  40  20 

I  Conveyor  to  barking  drums  * .  5  7  g 

I  Barking  drum  installation . 50  75  60 


10 

or 

5  ft.  barkers  (one  always  held  in  reserve) 

70 

120 

100  ^ 

I 

or 

*Centrifugal  pump  for  pond  if  wood  is 
floated  to  barking  drums  instead  of 
being  handled  on  conveyor. 

12 

12 

12 

I 

I 

Splitter . 

Conveyor  to  grinder  room . 

I 

6 

4 

9 

2 

8 

Total  for  Wood  Room . 

(24  hr.  av.) 

(  9  hr.  av.) 

Using  barking  drums  (operation  9  hours  only) .... 

78  155 

121 

16 

assumed  (54)  x  (27)  inch  3-pocket  6000 
to  be  con-  grinders,  capacity  6.67 

nected  in  tons  per  24  hours.  One 

lines  of  4  grinder  assumed  as  idle, 

each. 

6800 

6500* 

4 

I 

I 

I 

8 

Pumps  for  supplying  pressure  to  grftid- 
ers  (if  driven  directly  by  turbines) .  . 
Centrifugal  pump  for  white  water .... 

Centrifugal  pump  for  stuff . 

Silver  screen . 

Centrifugal  screens . 

70 

50 

30 

5 

120 

70 

50 

30 

5 

70 

50 

30 

5 

6 

25 

or 

Twelve  plate  screens,  coarse . 

Twelve  plate  screens,  fine . 

12 

50 

12 

50 

12 

50 

I 

Pump  for  general  water  supply  (capac¬ 
ity  3,000,000  gallons  per  24  hours) . . 
Fan  pump  to  deliver  stuff  to  wet  ma¬ 
chines,  or  deckers ...  . 

Total  grinders  and  screens .... 

80 

70 

6507 

80 

70 

7287 

80 

70 

6987 

Total  for  Wood  Room  and  Grinder  Room 

6507 

7442 

7032  1 

15  Wet  machines,  72-inch  face .  140 


180 


160  H 


pulp. 


•For  news  grade  of  g,  w.  pulp.  For  fine  grades,  as  8000  h.  p.  may  be  used  for  100  tons  of 


THE  POWER  PLANT 


459 


IF  PULP  IS  TO  BE  PREPARED  FOR  IMMEDIATE  MANUFACTURE 
INTO  PAPER 


Number  of 
Units 

12  Deckers  or  pulp  thickeners.  .  .  .  , 
I  Centrifugal  pump  to  beaters .  .  . . 
I  Agitator  in  deckered  stock  chest 


Horsepower  Required 


Min. 

Max. 

Average 

36 

36 

36 

25 

75 

40 

15 

15 

15111 

Total .  76  126  91 


Total  ^ 

Total  * 

"power  required  to  make  100  tons  lapped 

pulp  per  day  (I  +  II) . 

■power  required  to  make  100  tons  deckered 
stock  per  day  (I  +  III) . 

6647 

6583 

7622 

7568 

7192 

7123 

EQUIPMENT  FOR  1 00-TON  SULPHITE  MILL 
(9-hour  operation) 

I  Log  haul . 

I  Gang  saw  (1-60"  saw  cutting  4"  wood) 

I  Conveyor  to  barking  drums  * . 

I  Barking  drum  installation  (2)  drums.. 

I  Barking  machine  (5  ft.)  for  handling 

wood  imperfectly  prepared  in  drums 

8 

8 

5 

100 

7 

20 

40 

9 

150 

12 

16 

30 

7 

120 

10 

20 

or 

5  ft.  barkers  (i  always  in  reserve) .... 

140 

240 

200- 

I 

*Centrifugal  pump  for  pond  if  wood  is 

12 

12 

12 

floated  to  barking  drums  or  barkers 

instead  of  being  handled  on  conveyor. 

I 

Splitter . 

I 

4 

2 

I 

Conveyor  to  chippers* . 

8 

12 

10 

I 

Centriffgal  pump  if  wood  is  floated  to 

chippers . 

12 

12 

12 

3 

7  ft.  chippers  (i  running  only  part  of 

the  time) . 

120 

275 

200 

2 

Crushers . 

50 

80 

60 

3 

Shaker  screens  for  chips . 

12 

24 

15 

I 

Convevor  to  shaker  screens . 

3 

3 

3 

I 

Conveyor  to  chip  bins . 

20 

30 

25 

Total  for  Wood  Preparing  Plant . 

342 

659  498  (9  hr.  av.) 

Operating  9  hours  only . 

186  (24  hr.  av.) 

Acid  Plant,  Digester  House,  Etc. 

I 

Pump  for  general  water  supply  (ca- 

pacity  7,000,000  gallons  per  24  hours. 

(Newspulp) . 

100 

100 

100 

I 

Elevator  for  limestone . 

10 

10 

•2 

I 

Pump  for  tower  system . 

15 

15 

15 

5 

Digesters  49  ft.  high  x  15  ft.  diameter. 

holding  approximately  26  cords  chips 

and  yielding  12  tons  pulp  (air  dry) 

per  cook . 

I 

Centrifugal  pump  for  pumping  stock 

from  blow  pit  tanks  to  knotters .... 

25 

25 

25 

’Exclusive  of  power  required  for  heating  buildings  in  winter,  providing  ventila¬ 
tion  for  grinder  room,  regrinding  slivers  from  silver  screen,  transportation  of 
lapped  pulp  by  conveyors  or  trucks  to  storage  or  cars,  illumination,  etc.  Neither 
is  any  allowance  made  for  hydraulic  pressing  of  pulp  taken  from  wet  machines. 


46o  modern  pulp  AND  PAPER  MAKING 

Number  of  '  Horsepower  required 


Units 

Min. 

Max. 

Average 

4 

Knotters . 

6 

6 

6 

I 

Centrifugal  pump  for  pumping  stcok 
from  riffler  to  head  box  of  screens .  . 

40 

40 

40 

It  is  assumed  that  the  stock  is  sluiced  from  the  blow-pits  to  storage  tanks 
below  and  is  pumped  from  them  to  a  mixing  box  from  which  it  flows  to  the 
knotters,  hence  to  the  riffler,  from  the  lower  end  of  which  it  is  pumped  to  the 
head  box  of  the  screens. 


10 

Centrifugal  screens,  including  second- 

ary  screens . 

175 

175 

175 

I 

Screenings,  Jordan  or  other  grinder .  .  . 

75 

75 

75 

I 

Centrifugal  pump  from  screens  to  wet 

machines  or  deckers  (not  required  if 
mill  is  arranged  so  stock  can  gravi¬ 
tate  from  screens)  which  would  or¬ 
dinarily  be  the  case . 

30 

30 

30 

Total  for 

Wood  Preapring  Plant  and  Digester 

House,  etc . 

466 

1135 

654  IV 

IF  PULP 

IS  TO  BE  LAPPED  FOR  STORAGE 

OR 

SHIPMENT 

7 

Wet  machines,  72  inches  face . 

84 

84 

84 

IF  PULP  IS  TO  BE  PREPARED  FOR  IMMEDIATE  MANUFACTURE 


INTO  PAPER 

1 2  Deckers,  72  inches  face . 

30 

30 

30 

I  Centrifugal  pump  to  beaters . 

20 

70 

25 

2  Agitators  in  deckered  stock  chests .... 

30 

30 

30 

Total . 

80 

130 

85  VI 

Total*  power  required  to  make  100  tons  lapped 

sulphite  per  day  (IV  -J-  V)  = . 

Total*  power  required  to  make  100  tons  deckered 

550 

1219 

738 

stock  per  day  (IV  +  VI)  = . 

546 

1265 

739 

EQUIPMENT  REQUIRED  FOR  MAKING  loo  TONS  NEWSPAPER  PER 
24  HOURS 

4  Beaters  (25  ft.  x  ii  ft.)  usual  Hollander 


type . 

120 

150 

140 

4 

Stuff  chests  with  agitators . 

30 

45 

40 

2 

Pumps  for  pumping  stock  from  chests 
to  Jordans . 

40 

40 

40 

2 

Jordans . 

240 

300 

280 

I 

Dissolver  for  clay . 

5 

5 

5 

2 

Agitators  for  clay  water . 

10 

10 

10 

2 

Paper  machines,  total  power  required 
for  all  parts  of  drive  as  well  as  for 
stuff  pumps,  suction  pumps,  calen¬ 
ders,  reels,  slitters,  blowing  system, 
etc.,  but  not  boiler  horsepower  for 
dryers . 

850 

1000 

950 

I 

Pump  for  general  water  supply,  capac¬ 
ity  3,000,000  gallons  per  24  hours.  .  . 

60 

60 

60 

Boiler  horsepower  required  for  dryer .  . 

800  to  900  B.H.P. 

Exclusive  of  power  required  for  heating  and  lighting  buildings,  ventilating 
digester  house,  transporting  lapped  pulp  by  conveyors  or  trucks  to  storage  or  cars, 
hydraulic  pressing  of  lapped  pulp,  operation  of  save-alls,  etc. 


THE  POWER  PLANT 


461 

The  power  required  to  drive  paper  machines  ^  varies  greatly 
with  their  width,  speed  and  other  conditions  obtaining  at  individ¬ 
ual  mills.  In  general  news  machines  from  140  to  170  inches  in 
width  require  from  400  to  500  h.p.  for  the  entire  machine  from 
screens  to  winder,  both  constant  and  variable  speed  shafts,  when 
running  at  about  600  feet  of  paper  per  minute. 

Book  machines,  ranging  in  width  from  no  to  140  inches  wide 
require  from  150  to  250  h.p.  Machines  for  fine  writings,  from 
80  inches  to  no  inches  wide,  require  from  50  to  125  h.p. 

The  speed  of  modern  news  machines  generally  at  least  is  600 
feet  per  minute,^  and  more  recently  built  machines  are  frequently 
run  much  faster;  book  machines  run  from  150  to  250  and  writing 
machines  from  60  to  175. 

Use  of  Estimates  of  Power  Required 

With  a  little  ingenuity,  requiring  no  great  amount  of  mathe¬ 
matical  ability,  the  above  estimates  can  be  made  the  basis  for  a 
great  many  calculations.  For  instance,  the  total  power  required 
to  make  a  particular  grade  of  paper  in  given  quantity  per  day 
can  easily  be  figured  out.  Suppose  the  paper  is  a  news  containing 
20  per  cent  sulphite  and  80  per  cent  ground  wood.  Obviously, 
the  power  required  for  the  sulphite  for  100  tons  of  such  paper 
will  be  20  per  cent  of  the  paper  shown  in  the  tabulation  for  a 
production  of  100  tons  of  sulphite  per  day.  Similarly,  the  power 
required  for  the  ground  wood  will  be  80  per  cent  of  that  required 
to  make  100  tons  of  ground  wood  per  day.  Adding  these  to¬ 
gether,  and  to  the  sum  adding  the  power  required  to  make  100 
tons  of  paper  per  day,  will  give  the  total  mechanical  horsepower 
required.  To  this  can  be  added  the  boiler  horsepower  required 
for  the  digesters  and  the  dryers  on  the  paper  machine.  This  will 
give  the  total  horsepower  required  and  the  necessary  installation 
of  boilers  and  prime  movers  can  be  figured  from  this  from  data 
supplied  by  manufacturers  of  such  equipment,  after  a  suitable 
figure  has  been  added  to  take  care  of  heating  in  winter,  lighting, 
machine  shop,  blacksmith  shop,  carpenter  shop,  coal  and  ash  con¬ 
veyors,  etc. 

The  figures  given  for  the  manufacture  of  paper  will  hold  true 
for  most  usual  kinds  of  paper,  such  as  news  print,  ordinary  book, 
magazine,  writing,  wrapping,  bag,  hanging  and  other  such  papers. 
For  fine  writings,  specialties,  etc.,  the  power  consumption  will, 
of  course,  be  greater  per  ton  of  production. 

With  some  adaptation  the  estimates  made  for  a  sulphite  mill 
will  apply  to  a  sulphate,  kraft,  or  soda  mill.  From  the  blow  pits 
on  the  figures  will  be  about  the  same.  The  boiler  horsepower  for 
the  digesters  will  be  different  and  no  general  figures  could  be 
given  for  the  recovery  systems  as  these  vary  tremendously  in  the 
number  of  pumps,  agitators,  etc.,  they  employ. 


*  See  also  table,  page  448. 

-  Excepting  in  the  case  of  machines  of  considerable  age. 


XVII.  Testing  of  Paper  and  Paper  Materials. 


Inasmuch  as  this  is  not  a  work  on  analytical  chemistry,  or 
even  on  such  portions  of  analytical  chemistry  as  pertain  to 
the  paper  industry,  it  is  not  our  intention  to  give  detailed 
instructions  for  analyzing  the  various  materials  which  are  used 
in  a  pulp  and  paper  mill. 

The  Technical  Association  of  the  Pulp  and  Paper  Industry 
appoints  committees  from  time  to  time  to  investigate  standard 
methods  of  testing,  and  such  methods  as  are  approved  are 
discussed  in  detail  from  the  practical  point  of  view  in  “Paper” 
and  other  journals.  The  Canadian  Association  has  also  done 
some  excellent  work  along  these  lines,  which  is  also  reported 
in  detail  in  the  various  journals. 

Griffin  and  Little,  in  “The  Chemistry  of  Paper  Making,” 
give  a  great  deal  of  useful  information  on  this  subject  as 
well  as  an  excellent  general  outline  of  chemistry  as  it  relates 
to  the  pulp  and  paper  mill. 

The  testing  work  of  a  modern  pulp  and  paper  mill  can  be 
roughly  classified  as  follows: 

(1)  Chemical  testing  or  analysis,  covering  all  raw  mate¬ 
rials  such  as  sulphur,  lime,  soda  ash,  sulphate  of  soda,  bleach, 
alum,  size,  etc.  Also  coal,  water,  lubricating  oils,  building  ma¬ 
terials,  paints  and  miscellaneous  materials  used  in  the  con¬ 
struction  and  operation  of  a  large  modern  industrial  plant. 

(2)  Paper  Testing,  that  is  a  series  of  standard  tests  made 
on  the  product  being  produced  by  the  mill  at  regular  intervals 
so  that  an  accurate  record  can  be  kept  of  the  quality  of  the 
product  and  the  efficiency  of  the  plant,  and  so  if  anything  is 
going  wrong  it  can  be  detected  and  remedied  before  much  harm 
is  done.  The  nature  of  these  tests  will  be  described  more  in 
detail  later  on. 

(3)  Microscopic  Testing.  Frequently  examination  of  paper 
or  of  pulp  with  a  microscope  is  necessary  to  detect  the  presence 
of  particular  materials.  Certain  solutions  are  used  in  con¬ 
nection  with  the  microscope  to  give  characteristic  colorations 
with  different  fibers. 

Chemical  Control  of  the  Mill. 

Chemical  control  enables  a  manufacturer  to  know  and  realize 
the  value  of  his  product  so  that  he  can  guarantee  every  pound 
of  it.  Such  a  guarantee  is  a  liability,  for  it  must  be  lived  up 

462 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  463 

to  at  all  times,  in  spite  of  variations  in  raw  material,  labor 
difficulties,  weather  conditions  and  other  variable  factors. 

Chemical  control  is  one  of  the  chief  items  in  the  list  of 
factors  which  enable  a  manufacturer  to  convert  this  guarantee, 
which  he  is  compelled  to  give,  into  an  asset  instead  of  a  liability. 
Moreover,  continued  watchfulness  for  defects  helps  to  build  up 
the  good  will  of  the  concern  and  to  establish  a  firm  reputation 
as  a  reliable  producer. 

Paper  making  is  a  peculiar  industry  in  that  it  is  in  part 
mechanical  and  in  part  chemical.  The  chemical  and  mechanical 
aspects  of  the  problem  are  so  interwoven  that  it  is  hard  to  say 
where  one  begins  and  the  other  ends.  There  are  some  paper 
makers  who  have  risen  from  the  ranks  to  be  superintendents  who 
almost  ignore  the  chemical  aspect  of  the  industry,  leaving  what¬ 
ever  attention  is  paid  to  the  chemical  operations  of  the  plant  to 
the  part  of  a  chemist,  who  may  or  may  not  be  competent  to 
discharge  such  important  duties.  On  the  other  hand,  there  are 
men  trained  as  chemical  engineers  in  charge  of  large  paper 
industries  who  pay  little  attention  to  the  enormous  and  im¬ 
portant  problems  in  mechanical  engineering  constantly  arising. 
Either  of  these  attitudes  is  wrong. 

Chemical  control  does  not  mean  having  a  laboratory  with 
some  glassware  and  balances  and  a  man  (usually  a  young  chemist 
just  out  of  a  technical  school)  confined  to  the  laboratory,  test¬ 
ing  and  analyzing  such  samples  as  are  sent  to  him.  from  time 
to  time.  It  means  having  a  man  experienced  in  the  art  of 
making  pulp  and  paper,  and  at  the  same  time  with  a  broad  chem¬ 
ical  education,  so  that  he  can  investigate  all  mill  problems  and 
work  out  new  ideas,  and  such  a  man  must  have  sufficient 
prestige  and  authority  to  be  able  to  carry  out  such  improvements 
as  may  suggest  themselves  to  him  after  they  have  been  sub¬ 
mitted  to  careful  analysis  and  discussed  with  his  associates. 
Such  men  are  not  easy  to  find  and  the  mill  is  to  be  regarded 
as  fortunate  which  possesses  such  a  man. 

With  increased  introduction  of  chemical  control  in  pulp  and 
paper  mills  there  has  come  about  a  more  efficient  utilization  of 
fuel  and  of  many  of  the  raw  materials  consumed,  such  as 
clay,  sulphur,  limestone,  soda  ash,  bleach,  dyestuffs,  etc. 

Some  of  the  problems  the  mill  chemist  will  have  to  wrestle 
with  are  investigations  into  water  conditions  from  time  to  time, 
making  size  emulsions,  determining  proper  proportions  of  alum, 
the  proper  furnish  of  raw  stock,  the  proper  colors,  etc. 

In  the  sulphite  mill  the  need  of  a  chemist  or  chemical  en¬ 
gineer  is  perhaps  more  obvious  than  in  the  paper  mill  since  the 
process  is  more  distinctly  chemical.  Chemical  control  steps 
in  at  the  very  first  stage  of  the  process — regulation  of  the  burner 
gases  in  order  to  prevent  formation  of  SO3  and  consequent 
formation  of  the  undesirable  calcium  sulphate  or  gypsum  in  the 
digesters,  etc.  Following  this  is  the  proper  preparation  of  the 


464  MODERN  PULP  AND  PAPER  MAKING 

raw  acid  and  cooking  acid  and  the  whole  subject  of  reclaiming, 
the  maintenance  of  high  free  and  low  combined.  There  is  an 
opportunity  here  for  the  chemist  to  apply  as  much  theoretical 
chemistry  as  he  knows.  The  problems  are  very  complex  and 
it  is  generally  realized  that  many  improvements  are  yet  to  be 
made  which  must  wait  for  adequate  scientific  consideration 
of  the  general  laws  governing  the  various  reactions. 

One  of  the  most  important  opportunities  for  chemical  con¬ 
trol  is  in  the  cooking  operation  itself.  Moisture  in  the  wood 
must  be  ascertained  in  order  that  the  cook  may  know  the  nature 
of  the  raw  material  he  is  handling. 

Chemical  control  does  not  necessarily  imply  having  a  large 
force  of  trained  chemists.  There  are  many  chemical  tests  which 
any  intelligent  workman  can  be  taught  to  make  at  regular  in¬ 
tervals.  The  workman  may  not  understand  the  underlying 
causes  of  the  reactions,  but  that  does  not  prevent  him  from 
following  directions,  and  entering  up  the  burette  readings  on 
a  form.  Frequently  the  chemist  can  greatly  simplify  such  tests 
by  adjusting  his  standard  solutions  so  that  burette  readings  will 
give  percentages  directly  without  any  calculation.  For  in¬ 
stance,  acid  makers  can  be  taught  to  make  the  necessary  iodine 
and  caustic  titrations  to  estimate  total  and  free  SO2.  If  the 
standard  solutions  supplied  to  them  by  the  laboratory  are  made 
up  exactly  1/16  N.,  then  a  2  cc.  sample  of  acid  will  give  a 
burette  reading  which  will  give  the  percentage  of  SO2  directly 
when  the  decimal  point  is  moved  one  place  to  the  left.  This 

method  assumes  the  specific  gravity  of  the  acid  to  be  i,  which 

is,  of  course,  incorrect,  but  the  error  introduced  in  this  way 

is  not  enough  to  vitiate  the  result  for  practical  purposes. 

Similarly,  men  can  be  taught  to  make  simple  chemical  esti¬ 
mations  instead  of  using  a  hydrometer  in  making  up  bleach. 
The  use  of  the  hydrometer  in  this  connection  is  very  inac¬ 
curate,  on  the  other  hand  many  mills  have  no  chemist,  and 
in  many  mills  which  do,  the  trouble  of  taking  samples  and 
sending  them  to  the  laboratory  is  considered  not  worth  while. 

Practically  all  the  chemical  tests  connected  with  the  opera¬ 
tion  of  boiler  feed  water  treatment  systems  can  be  handled  by 
workmen  once  they  are  shown  the  routine  of  the  operation. 

The  writer  suspects  that  one  reason  so  many  mills  seem 
obstinately  backward  in  introducing  chemical  control  is  be¬ 
cause  so  many  chemists  shroud  their  operations  in  so  much 
mystery  that  they  antagonize  the  non-chemical  men  about  them. 
In  reality,  the  majority  of  chemical  tests  are  absurdly  simple 
compared  with  many  of  the  other  duties  of  intelligent  work¬ 
men,  and  there  is  no  reason  why,  wherever  a  chemical  test  is 
absolutely  necessary,  it  cannot  be  carried  out  if  the  chemist  will 
supply  a  simple  method  for  doing  it.  Of  course,  the  chemist 
should  not  load  the  help  down  with  so  much  work  of  this 
kind  that  they  will  have  no  time  for  their  more  ordinary 


'TESTING  Of  PAPER  AND  PAPER  MATERIALS  465 

duties.  We  have  seen  mills,  in  more  than  one  industry,  where 
foremen  and  others  were  kept  so  busy  filling  out  forms  and 
making  reports  of  a  complicated  nature  to  send  back  to  the  office 
or  laboratory  to  satisfy  some  alleged  “efficiency  expert”  that 
they  became  mere  clerks  to  the  great  detriment  of  the  opera¬ 
tions  over  which  they  were  supposed  to  exercise  control. 

Paper  Testing. 

Paper  may  be  examined  from  three  different  points  of  view, 
physical  quality,  mechanical  quality  and  composition. 

The  various  tests  classified  under  physical  testing  are :  weight, 
thickness,  bvilk,  strength,  stretch,  sizing,  etc. 

The  chief  mechanical  test  is  for  strength  and  this  is  sub¬ 
divided  into  tests  for  tear,  punch,  bursting,  etc. 

Under  composition  falls  the  determination  of  the  materials 
used  in  making  the  paper  and  their  proportions. 

In  addition  to  the  above  tests,  special  tests  may  be  used 
on  special  grades  of  paper,  viz.,  absorbency  and  permeability 
for  blotting  papers,  resistance  to  blood  in  butchers’  papers,  etc. 

In  most  cases  no  one  of  the  above  tests  will  give  an  accurate 
working  knowledge  of  the  paper.  Moreover,  frequently  some 
one  test  may  show  the  paper  to  be  of  excellent  quality,  but 
when  this  paper  is  put  to  use  it  is  found  to  be  worthless ;  con¬ 
sequently  the  nature  of  the  test  used  on  the  paper  must  be  in 
accordance  with  the  treatment  the  paper  will  encounter  in  actual 
use.  For  example,  for  testing  strength  there  are  several  ma¬ 
chines  in  general  use  which  give  the_  punch  test,  bursting  test, 
tear  test,  etc.  It  is  often  quite  desirable  to  have  a  sheet  of 
paper  comparatively  low  in  punch  test  but  high  in  tear,  for  ex¬ 
ample,  a  bag  paper.  A  punch  test  applied  to  such  a  paper,  or 
to  any  paper  for  that  matter,  shows  the  hardness  and  rigidity  of 
the  sheet.  However,  this  is  not  what  should  determine  the 
value  of  a  bag  sheet.  A  thin  sheet  of  celluloid  would  test 
very  high  on  such  a  machine  and  would  have  no  value  at  all 
for  bag  manufacture,  and  this  is  only  an  extreme  case  of  the 
conditions  prevailing  with  some  papers.  Consequently,  the  sheet 
to  be  tested  must  be  dealt  with  in  such  a  manner  that  its  tearing 
resistance  will  be  shown  and  the  extent  to  which  the  fibres 
will  peel  when  they  are  torn  apart.  A  wrapping  or  bag  paper 
that  peels  when  torn  will  be  much  better  than  one  that  does 
not.  A  punch  test  will  not  show  this  peeling  quality  at  all.  In 
fact,  if  two  sheets  of  bag  or  wrapping  paper  were  made,  one 
stiff’ and  hard  with  little  crossing  of  the  fibres,  the  fibres  beaten 
short  and  the  sheet  well  colored  and  sized,  and  the  other  sheet 
made  soft  and  flexible,  with  the  fibres  brushed  out  long  and  in¬ 
terwoven  on  the  wire,  the  punch  test  would  show  the  first 
sheet  to  be  the  better  of  the  two,  as  it  would  give  a  higher  test. 
In  reality  the  second,  from  the  point  of  view  of  service,  would 


466  MODERN  PULP  AND  PAPER  MAKING 

be  far  the  better  sheet  and  a  tear  test  would  indicate  this, 
as  would  also  a  peeling  of  the  fibres. 

The  above  remarks  will  illustrate  the  necessity  not  only 
of  making  tests,  but  also  of  making  the  right  kind  of  tests. 

The  following  are  descriptions  of  some  of  the  commoner 
paper  testing  machines  with  some  remarks  as  to  the  purposes  for 
which  they  are  useful. 

The  Mullen  Testing  Device:  The  construction  and  opera¬ 
tion  of  the  Mullen  Paper  Tester  is  almost  too  well  known  to 
require  description.  By  means  of  a  hand  wheel  the  pressure  is 


Fig.  187.— -Photograph  showing  manner  in  which  fibres  peel  when  a  sheet 
of  wrapping  paper  is  torn  naturally  by  the  hands. 

increased  on  a  column  of  glycerine  which  drives  a  small  rubber 
ball  through  the  sheet  of  paper  which  is  tightly  held  between 
two  flat  surfaces.  The  pressure  is  read  on  a  dial  graduated  so 
as  to  give  the  breaking  strength  in  pounds  per  square  inch. 

The  operation  of  this  machine  is  very  simple  and  tests  can 
be  made  very  quickly.  Consequently,  it  has  been  very  widely 
adopted  throughout  the  paper  industry  and  for  some  grades  the 
Mullen  Test  is  really  a  very  fair  criterion  of  the  strength 
(or  the  particular  variety  of  strength  required).  However,  as 
previously  explained,  for  many  kinds  of  paper  the  Mullen  Test 
is  of  very  little  value  and  is  frequently  positively  misleading. 

The  Schopper  Tester:  This  machine  measures  the  strength 
required^  to  tear  paper  and  other  materials.  It  is  very  accurate 
and  registers  the  tearing  strength  throughout  the  whole  period 
that  the  paper  is  being  torn.  However,  this  machine  is  very 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  467 

intricate  and  expensive  and  is  not  adapted  to  making  quick 
tests  and  consequently  is  not  suitable  for  the  ordinary  com¬ 
mercial  and  manufacturing  purposes  of  the  paper  industry. 

The  Witham  Tear  Testing  Machine:  This  machine  imitates 
the  tear  given  to  a  sheet  of  paper  by  the  human  fingers  but  in 
such  a  manner  that  the  weight  necessary  to  effect  this  tearing  is 
registered  accurately  automatically  down  to  small  fractions  of 
a  gram.  The  construction  and  method  of  operation  of  this  ma¬ 
chine  can  readily  be  seen  from  the  illustration. 


Fig.  188.— Original  form  of  the  Witham  tear  testing  machine. 

The  paper  is  torn  to  a  certain  distance  whereupon  a  round 
hole  is  punched  in  the  sheet — insuring  an  absolutely  fair  start 
or  co-efficient  for  the  tear.  This  is  important  because  a  sheet 
of  paper  partially  torn  will  allow  the  tear  to  continue  with  much 
less  stress  than  would  be  required  to  start  the  tear  in  the  first 
place.  When  the  paper  is  fixed  in  the  device  the  liquid  is  turned 
on  and  the  weight  on  the  balance  gradually  increases  by  the 
dropping  of  the  liquids.  When  the  paper  tears  the  operator 
turns  off  the  liquid  and  reads  the  burette. 

The  Widney  Testing  Machine}  This  is  a  very  useful  machine 
for  determining  the  stiffness,  resilience  and  point  of  yield  in  any 

^See:  “The  Widney  Tester,”  C.  D.  Allen,  “The  Paper  Industry,”  June,  1919, 
page  208. 


468  MODERN  PULP  AND  PAPER  MAKING 

pliable  material.  The  tearing  resistance  of  paper  can  be  defi¬ 
nitely  determined  in  ordinary  units.  This  machine  is  especially 
applicable  to  heavy  papers,  boards,  etc.,  where  stiffness  is  one  of 
the  most  important  properties.^ 

The  Webb  Tester.  This  is  a  testing  machine  of  the  puncture 
type,  which  gives  more  satisfactory  results  than  the  Mullen  Tester 
and  which  can  be  used  for  certain  products  such  as  fibre  board, 
for  which  it  is  not  possible  to  adapt  the  Mullen  machine.  In  ad¬ 
dition  to  the  puncture  test,  the  Webb  machine  may  be  used  for 
tensile  tests,  elongation  tests  and  compression  tests.  While  its  use 
was  developed  in  connection  with  the  testing  of  fibre  boards  and 
corrugated  fibre  containers,  its  usefulness  is  not  confined  to  this 
class  of  materials.  It  can  be  used  for  testing  any  kind  of  paper, 
cardboard,  building  boards,  fabrics,  etc. 

System  of  Making  and  Recording  Tests. 

The  following  is  a  description  of  the  tests  and  the  method 
of  recording  them  which  the  writer  has  found  suitable,  after 
many  years  of  experimentation,  for  controlling  the  quality  of 
the  product  of  a  large  paper  mill. 


The  Technical  Bureau. 


One  of  the  chief  points  to  take  care  of  in  maintaining  a 
Bureau  of  Tests,  is  such  an  organization  that  the  mill  men  as  a 
whole  do  not  take  it  as  a  spying  system  upon  their  activities.  In 
other  words  if  the  personnel  and  the  activities  of  the  Bureau  of 
Tests  can  be  so  woven  into  the  manufacturing  end  of  the  game 
so  as  to  serve  for  reproducing  facts  which  in  turn  may  be  posted 
on  the  Bulletin  Board  for  the  employee,  a  tremendous  amount  of 
good  will  come  from  this  organization. 

We  have  stated  that  it  has  been  our  experience  that  a  happy 
medium  may  be  arrived  at,  by  which  a  tremendous  amount  of 
time  is  not  wasted  and  money  spent  on  elaborate  analyses  of  ma¬ 
terials  which  usually  the  seller  is  capable  of  furnishing  without 
the  mill  necessarily  maintaining  an  elaborate  analytical  depart¬ 
ment  for  this  purpose.  As  we  have  said  before  the  ultilization 
of  the  Bureau  of  Tests  for  checking  the  paper  as  it  is  being 
made,  thereby  preventing  the  manufacture  of  poor  paper  and  in¬ 
cidentally  checking  various  points  of  manufacture,  as  relating  to 
the  cost  during  the  operation,  to  our  minds  constitutes  its  chief 
function. 

This  system  calls  for  two  departments — a  Bureau  of  Chem¬ 
istry  and  a  Bureau  of  Physical  Tests.  These  departments  work 
more  or  less  in  conjunction  with  each  other  but  yet  each  have 
their  definite  duties.  The  Bureau  of  Chemistry  finds  its  work 
principally  in  the  scientific  valuation  of  purchased  raw  materials 


ru  illustrated  article  by  J.  D.  Malcolmson  in  “Jl.  of  Ind.  &  Eng. 

Chem.,  Vol.  II,  No.  2,  page  133,  February,  1919. 


SULFHITL  -MILLS 
cmaLficr  or  cmppin  oPLnnmns 


469 


MODERN  PULP  AND  PAPER  MAKING 


470 

going  into  the  manufacture  of  pulp  and  paper  and  also  is  engaged 
in  testing  the  efficiency  of  these  various  purchased  raw  materials 
as  utilized  by  machinery  and  workmen  in  the  plants — such  as  coal, 
sulphur,  limestone,  rosin,  alum,  etc.  In  conjunction  with  the 
above  all  stages  at  which  the  quality  of  the  pulp  is  apt  to  be 
destroyed,  are  constantly  inspected  and  checked.  The  quality  of 
the  wood  is  carefully  watched — its  moisture  content  and  sound¬ 
ness.  By  means  of  laboratory  screens,  the  efficiency  of  the  sizes 
of  chips  made  in  the  chippers  is  carefully  regulated  in  order  to 
aid  the  digester  cook  further  on  in  the  process,  to  secure  more 
uniform  cooking  conditions.  A  large  blue  print  (Figure  189) 
is  posted  on  the  Bulletin  Board  for  the  benefit  of  the  work¬ 
men,  illustrating  various  percentages  of  different  size  chips  from 
day  to  day.  It  is  quite  essential  in  the  modern  sulphite  mill  of  to¬ 
day  to  have  installed  a  system  for  checking  the  various  operations 
of  the  sulphite  process,  such  as  burner  gas  temperature,  SO, 
content,  condition  of  the  acid  in  the  towers  and  finishing  tanks, 
temperature  of  cook,  blow,  etc.  The  following  charts  are  typical 
of  the  manner  in  which  these  facts  are  recorded: 

Figure  190 — Acid  Room  Report;  Figure  191 — Screen  Room 
Report;  Figure  192 — Press  Room  Report;  Figure  193 — Stock  in 
Water  Report. 

These  all  go  to  show  the  extreme  care  necessary  in  checking 
up  this  one  operation  not  only  from  the  standpoint  of  maintain¬ 
ing  quality  but  also  of  keeping  down  rising  costs  of  manufacture 
by  the  elimination  of  needless  waste  of  materials.  These  charts 
are  self-explanatory  and  by  their  means  the  executive  is  enabled 
to  trace  the  history  of  any  cook  blown  beginning  with  the  wood 
pile  up  to  the  time  it  reaches  the  wet  presses,  at  which  stage 
further  inspection  takes  another  course. 

In  the  beater  room,  as  an  aid  and  check  upon  amounts 
furnished  to  the  beaters,  the  beatermen  are  supplied  with  data, 
as  in  Figure  194.  Another  such  chart  indicates  the  amount  of 
rosin  to  add  for  the  different  basis  weights  of  paper  being  run. 

One  of  the  next  steps  is  a  careful  checking  of  each  roll  of 
finished  paper  as  it  is  finished  on  the  machine.  As  the  finished 
reel  is  cut  up  into  rolls,  each  roll  is  stamped  with  the  name  of  the 
mill,  the  machine  tender’s  name,  date,  grade,  weight  and  also  reel 
number,  thus  enabling  operators  who  finally  pass  upon  the  quality 
of  the  paper  to  reject  any  rolls  that  appear  to  be  below  standard. 
At  the  end  of  each  machine  we  have  a  paper  inspector  responsible 
to  the  Bureau  of  Chemistry,  who  takes  from  the  finished  reel 
three  samples  12  inches  wide  and  in  length  each  sample  taking 
in  the  full  width  of  the  reel. 

He  then  takes  one  sample,  folds  it  and  carefully  weighs  it 
in  grams  on  an  analytical  balance  sensitive  to  .01  of  a  gram. 
The  sample  is  then  placed  in  an  electric  oven  and  allowed  to 
remain  for  about  two  minutes  depending  upon  the  weight  of  the 
paper.  The  dry  sample  is  then  weighed  and  the  percentage  of 


ACID  ROOM  REPORT  D*tB  ^^3,0 


471 


472 


PRESS  ROOM  REPORT 


473 


BUREAU  OF  -TEST—* Per  cent  of  ^tock  io  White  Water 


474 


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475 


476  MODERN  PULP  AND  PAPER  MAKING 

moisture  computed.  The  results  of  this  test  are  recorded  on 
the  other  two  samples  and  plotted  on  the  Paper  Inspection  Chart, 
from  which  the  machine  tender  can  obtain  the  results  of  the 
test. 


Division — 

Sample  No 
Time - 

Standard  Actual 

Basis  Weight,  24  X  36 .  .  . 

Mullen  Test .  .  . 

Points  Mullen  per  Found .  .  . 

Moisture,  % .  .  . 

Speed,  Ft.  per  Min .  .  . 

Prod,  per  Hour,  Lbs .  .  . 

Sets  per  Hour .  .  . 

Sizing  Quantities .  . .  . 

Girt .  .  . . 

Color .  .  . 

Folding .  .  . 

Machine  Tender _ _ _ _ _ 

Back  Tender _ _ _ 

Remarks _ _ _ 


Ins  pector _ 

Fig.  195- 

The  inspector  then  takes  another  sample,  weighs  it  to  .01 
gram  and  multiplies  the  weight  obtained  by  .528  thereby  convert¬ 
ing  the  weight  to  pounds  per  ream.  This  he  notes  on  the  form 
stamped  on  each  sample  shown  in  Figure  195.  The  sample  after 
being  weighed  is  taken  and  tested  with  the  Mullen  Tester,  an 
average  of  six  readings  being'  taken  and  reported  on  the  sheet. 


PAPER  INSPECTION 

- Date - 

—  Mach.  No. - - -  Tour- 

-  Grade - 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  477 

Following  this  is  the  Sizing  Test,  which  consists  of  floating  a  piece 
of  the  paper  about  3  inches  square  on  the  surface  of  a  5  per  cent 
solution  of  potassium  ferrocyanide  and  when  the  solution  appears 
to  come  through  the  fibers  a  small  brush  dipped  in  a  5  per  cent 
solution  of  ferric  chloride  is  brushed  across  the  surface  of  the 
paper.  As  soon  as  penetration  has  taken  place  a  deep  coloration 
(Prussian  Blue)  forms.  The  time  taken  for  the  operation  is 
noted  in  seconds  and  plotted  as  such.  There  are  other  methods 
of  making  sizing  tests,  but  the  writer  has  found  the  above  satis¬ 
factory  for  most  grades  of  paper.  Along  with  these  other  opera¬ 
tions  the  inspector  notes  the  speed  of  the  machine  for  the  hour 
and  the  number  of  sets  run  off  and  from  the  above  data  com¬ 
putes  the  production  for  the  hour.  The  formula  used  is  as 
follows : 


Ream  Weight  X  Speed  (in  feet  per  Minute)  X  Deckle  (in  inches)  X  Number  of 

Minutes 


34560 


Any  shut-downs  are  noted  and  remarks  made  on  same. 

This  completes  the  actual  operations  of  the  paper  inspector. 
He  places  the  two  sets  of  samples  that  have  all  the  data  placed 
upon  them  in  a  tightly  covered  galvanized  iron  can,  and  at  the 
end  of  each  tour  one  complete  set  is  forwarded  to  the  Bureau 
of  Chemistry  and  one  to  the  Department  of  Physical  Tests. 

Upon  receipt  of  the  samples  by  the  Bureau  of  Chemistry,  they 
are  immediately  weighed  and  placed  in  a  large  steam  heated  oven 
at  a  temperature  of  220° F.  The  samples  are  allowed  to  remain 
there  for  twelve  hours,  by  which  time  they  have  reached  a  con¬ 
stant  weight.  The  figures  obtained  by  the  Test  Bureau  and  those 
obtained  by  the  Paper  Inspector  are  examined  and  any  discrep¬ 
ancies  are  quickly  followed  up. 

The  Bureau  of  Chemistry  next  compiles  the  data  obtained 
from  each  sheet  upon  a  Machine  Tender’s  Paper  Inspection  Re¬ 
port  shown  in  Figure  196.  The  object  of  this  report  is  to  serve 
as  a  summary  of  the  work  of  a  machine  tender  covering  (in  a 
general  way)  the  external  qualities  of  the  paper  produced  by 
him,  the  amount  produced,  and  any  shut-downs  that  may  have 
occurred  under  him.  As  soon  as  these  reports  are  compiled 
a  copy  is  forwarded  to  each  mill  superintendent,  thereby  enabling 
him  to  keep  a  close  survey  of  his  operations. 

The  Bureau  of  Chemistry,  periodically  checks  the  operation 
of  all  inspectors,  taking  one  inspector  each  week.  In  following 
these  proceedings  the  paper  inspectors  are  never  informed  as  to 
who  is  being  watched,  which  fact  keeps  them  under  a  continuous 
surveillance  in  all  their  operations. 

We  will  now  return  to  the  third  set  of  samples :  When  re¬ 
ceived  by  the  Department  of  Physical  Tests,  they  are  arranged 
in  order  of  roll  numbers  and  from  these  five  strips  are  torn 


478  MODERN  PULP  AND  PAPER  MAKING 

12"  X  4".  Two  of  these  strips  are  carefully  noted  as  to  color, 
formation  and  any  other  characteristics  that  apply  to  a  good 
sheet  of  paper,  by  a  practical  paper  man,  who-  has  served  many 
years  in  the  actual  running  of  a  machine  and  has  officiated  in 
various  departments  of  the  paper  mill.  Two  sets  of  these  strips 
are  marked  with  the  following  data grade,  weight  and  reel 
number — they  are  in  turn  forwarded  to  the  General  Manager  and 


Macb.  Nn.  / 


TEST  BUREAU 


PAPER  INSPECTION 


Cut  V!r,  C 
Date 


Mill- 


Tout.  -Machine  Tender 


R«l 

/S' 

Time 

WEIGHT 

MULLEN 

Rfttic 

_] - 

Moui  f^eeo 

Seu 

Prod. 

1 

SlK 

SUud 

Act 

SUud 

Act 

SV? 

Sxc. 

■7/r 

7f 

g9 

/ 

/  /yr? 

J.£. 

7? 

n 

va- 

S./ 

89 

J 

//^ 

JUT 

SLO 

// 

// 

S7- 

.•/6 

P.X 

89 

/^. 

//£s 

•3.9 

af 

fr 

SA'S 

m 

ft- 

SA, 

S  9 

Sf 

/ 

//a.6 

3.7 

H 

/f 

9/ 

f  9 

99 

///3 

3.C 

Sn- 

H 

96, 

^  7 

99 

//eg 

j.ac 

/* 

•t 

4 

i'9'7 

Sf 

/  * 

//09 

XS~ 

Aver 

ee 

^•73 

(,S- 

■  Us 

g‘a 

S9  1 

//A  9 

•27 

Remarks 


J^icurad  by.  0^73. 


Tested  by. 


Ap?»- 


Fig.  196. 


to  the  General  Superintendent.  The  remaining  strip  is  tested  on 
the  Witham  Tear  Machine. 

Until  very  recently  the  tearing  quality  of  a  sheet  of  paper 
could  not  be  expressed  by  a  numerical  expression.  This  quality, 
all  important  in  certain  grades  of  paper,  was  left  to  the  judgment 
of  any  person  picking  up  the  sheet.  In  the  past  the  chief  machine 
that  has  been  available  for  determining  the  strength  of  a  sheet  of 
paper  has  been  the  Mullen  Tester.  We  have  found  that  fre¬ 
quently,  although  a  paper  may  give  a  high  Mullen  test,  it  offers 
very  little  resistance  to  tear.  In  other  words  this  Mullen  Tester 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  479 

does  not  give  the  strength  of  the  tearing  qualities  lengthwise  of 
the  sheet.  Now  with  the  introduction  of  Tear  Machines  a  nu¬ 
merical  expression  can  be  obtained  indicating  the  actual  tearing 
resistance  that  the  sheet  may  offer. 

It  has  been  found  that  in  all  tests  involving  the  mechanical  re¬ 
sistance  of  paper,  it  is  essential  (in  cases  requiring  a  great  degree 
of  accuracy)  to  take  into  consideration  the  influence  of  the  hygro¬ 
scopic  moisture  in  the  paper.  With  this  point  in  view  a  Normal 
Air  Humidifier  can  advantageously  be  installed  but  if  no  auto¬ 
matic  device  is  added  to  control  the  temperature,  the  results  will 
refer  to  Percentage  Relative  Humidity,  and  not  to  the  Absolute 
Humidity. 

After  proper  labelling,  the  two  sets  of  samples  prepared  by 
the  practical  paper  man  are  submitted  to  the  General  Superin- 


. . bate. 

Grade  . . . 

Sample  No . . 

Time  . . 

Mach.  Tender  . 

Cause  for  criticism  . 


CRITICISM  SHEET 

Mr .  Supt.  .. 

Grade  . 

Sample  No .  . . 

Time  . . 

Machine  Tender  . 

Cause  for  criticism  . . 


Date . 

..  Mill . 


Physical  Testing  Dept.  .  Approved  by . . . 

By  . .  . . ..Gen.  Supt. 


Fig.  197. 


tendent  and  General  Manager  for  further  inspection.  These 
particular  examinations  in  conjunction  with  those  of  the  practi¬ 
cal  paper  man  are  of  great  utility,  as  an  approximate  estimate  can 
be  formed  thereon.  Unfortunately  this  inspection  lacks  the 
fundamental  necessity  of  numerical  expression,  which  must  form 
the  basis  of  any  records  when  any  particular  point  is  disputed 
by  equally  experienced  men  representing  different  interests.  The 
set  of  samples  as  received  by  the  General  Superintendent  and 
JManager  are  given  a  thorough  examination  from  a  practical 
standpoint.  With  a  long  experience  in  “handling”  paper,  one  is 
able  to  judge  quality  and  value  within  a  very  few  minutes.  With 
the  feeling  of  the  sheet,  the  weight  and  ream  weight  are  esti¬ 
mated.  The  drawing  of  the  sheet  of  paper  between  the  finger 
and  the  thumb  will  reveal  the  smoothness  of  the  surface  and  its 
bulking  qualities.  By  holding  the  sheet  up  to  the  light,  and  look¬ 
ing  through  it,  one  can  see  the  nature  of  the  beating,  the  length 
of  the  stuff,  and  the  manipulation  of  the  stuff  upon  the  “wire.” 

With  the  practical  tests  carried  out  in  this  manner,  if  any 
question  of  doubt  has  arisen  regarding  the  quality  of  any  roll, 
the  numerical  figures  that  have  been  compiled  by  the  Department 
of  Physical  Tests,  covering  all  tests  made  by  them,  are  analyzed 


480  MODERN  PULP  AND  PAPER  MAKING 

and  if  the  quality  of  the  paper  is  questionable,  a  criticism  sheet 
(Figure  197)  is  forwarded  to  the  Mill  Superintendent,  stating 
whatever  criticisms  have  occurred.  In  accordance  with  the 
criticism  sheet,  a  reject  slip  (Figure  198)  is  sent  to  the  Ship¬ 
ping  Department,  requesting  that  department  to  reject  any  paper 
that  is  under  quality.  In  this  manner  no  paper  is  allowed  to  leave 


Date 


No.  of  roUs  Rej . 

Made  at  . 

Date  . 

Grade  . 

Roll  No . 

Cause  for  rejection 


Mill 


Mr . 

Reject  the  Following  Rolls  of  Paper 

Made  at  . 

Grade  . 

Weight  . 

Roll  No . 

CAUSE  FOR  REJECTION  . 

Signed  . . . 


REJECTION  NOTICE.  Date . . 

Supt  .  M)ll- 

Mill . Date  Made 


Gen’t  Sup(. 


Fig.  198. 


pAPsn  iNSPCcnoN 

PHYSICAL  TCSTS  FROM  MAN’Pa  OEPT. 


April 


learar  KrtfS 


loter  Kraft 


iMtfereil 

FoetM 


81.^  M. 


1a2 


997? 


99.6  le 


!t«  I  Act  I  *  E 

JTH  II.H  US 


i.flt  IP 


nrnii.  iis.i 


^nTiTir 


1187 1  icS 


iriTi 


108. 1 


llB^l 


174 


Tatcl  Cfnelcnev 


106.8 

11171 - TM.T 


117^  106 


lOTTl 

107.8 


TotAl  CMeicney  vt  CerxblncA  Mm 


Ci««niin«M_ 


?•  OABDDBB 


Fig.  199- 

the  mill  until  it  has  passed  successfully  through  a  thorough  ex¬ 
amination. 

The  daily  data  that  is  turned  in  each  morning  from  the  De¬ 
partment  of  Physical  Tests,  such  as  grade,  weight,  Mullen,  mois¬ 
ture  and  size  tests,  tear,  and  production,  is  made  up  into  the  Daily 
Efficiency  Chart  (Figure  199).  This  chart  in  a  condensed  form 
shows  the  actual  efficiency  of  each  mill  based  on  the  various 


PENALTY  CHART  FOR  MOISTURE 

PENALTY  .1  OF  1%  FOR  EVERY  .1  OF  1%  OFF 

Under  j 

Standard  Standard 

Moisture  Efficiency  Moisture 

8.0 

100 

8.0 

7.0 

99.9 

8.1 

7.8 

99.8 

8.2 

7.7 

99.7 

8.3 

7.6 

99.6 

8.4 

7.5 

99.5 

8.5 

7.4 

99.4 

8.6 

7.3 

99.3 

8.7 

7.2 

99.2 

8.8 

7.1 

99.1 

8.9 

7.0 

99.0 

9.0 

6.9 

98.9 

9.1 

6.8 

98.8 

9.2 

6.7 

98.7 

9.3 

6.6 

98.6 

9.4 

6.5 

98.5 

9.5 

6.4 

98.4 

9.6 

6.3 

98.3 

9.7 

6.2 

98.2 

9.8 

6.1. 

98.1 

9.9 

6.0 

98.0 

10.0 

5.9 

97.9 

10.1 

5.8 

97.8 

* 

10.2 

5.7 

97.7 

10.3 

5.6 

97.6 

10.4 

5.5 

97.5 

10.5 

5.4 

97.4 

10.6 

5.3 

97.3 

10.7 

5.2 

97.2 

10.8 

5.1 

97.1 

10.9 

5.0 

- 

97.0 

11.0 

To  find  Efficiency 

Ex:  Sheet  with  7.5%  Moisture  =  99.5%  Eff. 

Fig.  200, 


TB-(j 


482  MODERN  PULP  AND  PAPER  MAKING 


Physical  Tests.  These  reports  are  submitted  to  the  Mill  Super¬ 
intendents  who  are  found  to  take  a  great  interest  in  them.  In 
compiling  the  data  on  these  charts,  various  penalties  have  been 
made  depending  upon  the  overrunning  of  our  minimum  stand¬ 
ards.  Figure  200  illustrates  the  Moisture  Penalty  Chart.  Eight 
per  cent  has  been  taken  as  the  standard  percentage  of  moisture. 
The  average  moisture  for  each  grade  of  paper  in  each  mill  is 
taken  and  for  every  .1  per  cent  above  or  under  the  standard 
(8  per  cent)  a  penalty  of  .1  per  cent  is  made  for  that 
grade. 

Figure  201  is  used  as  a  Weight  Penalty  Chart.  An  allowance 
of  3  per  cent  is  made  for  all  grades  and  all  weights  either  above 
or  below  the  standard.  If,  after  averaging  the  weight  of  a  grade 
and  making  an  allowance  of  3  per  cent  the  weights  are  still  in 
excess  or  under,  a  penalty  of  .1  per  cent  for  every  .1  per  cent 
is  made. 

Figure  202  indicates  the  various  sizing  qualities  that  are  re¬ 
quired  of  the  different  weight  sheets.  Again  the  average  weight 
is  obtained  for  each  grade  and  the  correspondng  actual  sizing  in 
seconds.  This  is  compared  to  the  .standard  sizing  for  that  weight 
sheet  and  penalized  accordingly. 

At  the  end  of  each  week  the  daily  charts  are  averaged  and  the 
data  so  obtained  is  indicated  on  the  Weekly  Efficiency  Chart 
shown  in  Eigure  203.  Eigure  204,  known  as  Rejected  Paper 
Penalty  Chart,  is  based  on  the  percentage  of  rejected  paper 
based  on  the  total  production  for  the  week.  The  percentage  thus 
obtained  is  deducted  from  the  total  efficiency  of  the  mill  and  the 
actual  efficiency  of  the  mill  is  denoted  in  red. 

At  the  end  of  each  month  the  total  efficiencies  of  each  week 
are  added  and  averaged  and  plotted  on  a  chart  represented  by 
Eigure  205.  There  are  other  methods  for  presenting  these 
weekly  and  monthly  ratings.  These  are  Mechanical  Bar  Charts 
manufactured  by  a  concern  dealing  in  such  equipment.  By 
means  of  various  colored  ribbons  different  units  can  be  separated 
and  quickly  picked  out  by  the  mill  men,  thus  enabling  them  to 
get  the  comparative  rating  between  mills.  If  this  outlay  of  me¬ 
chanical  bar  charts  appears  expensive,  the  ordinary  type  of  bars 
on  blueprint  paper  will  serve  the  same  purpose. 

This  concludes  the  checking  and  methods  of  presentation  of 
the  daily  work  of  the  paper  mill,  the  amount  of  paper  produced, 
and  the  quality  of  workmanship.  Further  than  this  the  Depart¬ 
ment  of  Physical  Tests  obtains  from  the  Bureau  of  Chemistry 
data  enabling  them  to  present  in  somewhat  similar  form  (as  has 
already  been  explained)  the  efficiency  of  the  various  sulphite  and 
ground  wood  mills. 

Figure  206  indicates  a  daily  efficiency  chart  covering  the 
working  of  the  ground  wood  mills.  The  information  as  shown 
by  this  chart  gives  for  each  individual  unit  the  following: — total 
production ;  production  per  foot  ahead ;  production  per  K.  W. 


PENALTY  CHART  FOR  WEIC.HTS 


WEIGHT  OF  PAPER 


Lbs. 

+ 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

53 

54 

55 

56 

57 

58 

.8 

.0 

.9 

.1 

.0 

1.0 

.2 

.1 

.0 

1.1 

.3 

2 

.1 

.0 

f 

1.2 

.4 

.3 

.2 

.1 

.0 

1.3 

.5 

.4 

.3 

2 

.1 

.0 

_  1 

1.4 

.6 

.5 

.4 

.3 

.2 

.  1 

.0 

1.5 

.7^ 

.6 

.5 

.4 

.3 

.2 

.1 

.0 

1.6 

.8 

.7 

.6 

.5 

.4 

.3 

.2 

.1 

.0 

1.7 

.9 

.8 

.  7 

.6 

.5 

.4 

.3 

.2 

.1 

.0 

1.8 

1.0 

.9 

.8 

.7 

.6 

.5 

.4 

.3 

.2 

.1 

1.9 

1.1 

1.0 

.9 

.8 

.  7 

.6 

.5 

.4 

.3 

.2 

2.0 

1.2 

1.1 

1.0 

.9 

.8 

.7 

.6 

.5 

.4 

.3 

2.1 

1.3 

1.2 

1.1 

1.0 

.9 

.8 

.7 

.6 

.5 

.4 

2.2 

1.4 

1.3 

1.2 

1.1 

1.0 

.9 

.8 

.  7 

.6 

.5 

2.3 

1.5 

1.4 

1.3 

1.2 

1.1 

1.0 

.9 

.8 

.7 

.6 

2.4 

1.6 

1.5 

1.4 

1.3 

1.2 

1.1 

1.0 

.9 

.8 

.7  . 

2.5 

1.7 

1.6 

1.5 

1.4 

1.3 

1.2 

1.1 

1.0 

.9 

.8 

2.6 

1.8 

1.7 

1.6 

1.5 

1.4 

1.3 

1.2 

1.1 

1.0 

.9 

2.7 

1.9 

1.8 

1.7 

1.6 

1.5 

1.4 

1.3 

1.2 

1.1 

1.0 

2.8 

2.0 

1.9 

1.8 

1.7 

1.6 

1.5 

1..4 

1.3 

1.2 

1.1 

2.9 

2.1 

2.0 

1.9 

1.8 

1.7 

1.6 

1.5 

1.4 

1.3 

1.2 

3.0 

2.2 

2.1 

2.0 

1.9 

1.8 

1.7 

1.6 

1.5 

1.4 

1.3 

3.1 

2.3 

2.2 

2.1 

2.0 

1.9 

1.8 

1.7 

1.6 

1.5 

1.4 

3.2 

.2.4 

2.3 

2.2 

2.1 

2.0 

1.9 

1.8 

1.7 

1.6 

1.5 

3.3 

2.5 

2.4 

2.3 

2.2 

2.1 

2.0 

1.9 

1  8 

1.7 

1.6 

3.4 

2.6 

2.5 

2.4 

2.3 

2.2 

2.1 

2.0 

1.9 

1.8 

1.7 

3.5 

2.7 

2.6 

2.5 

2.4 

2.3 

2.2 

2.1 

2.0 

1.9 

1.8 

3.6 

2.8 

2.7 

2.6 

2.5 

2.4 

2.3 

2.2 

2.1 

2.0 

1.9 

3.7 

2.9 

2.8 

2.7 

2.6 

2.5 

2.4 

2.3 

2.2 

2.1 

2.0 

3.8 

3.0 

2.9 

2.8 

2.7 

2.6 

2.5 

2.4 

2.3 

2.2 

2.1 

3.9 

3.1 

3.0 

2.9 

2.8 

2.7 

2.6 

2.5 

2.4 

2.3 

2.2 

Exarr 

pie 

eavy 

40  lb. 

Sheet  w 

eighing 

2  lbs.  1 

Pena 

1  ty  =  .t 

of  1% 

Fig.  201 
483 


Tn-2 


SIZE  PENETRATION  PENALTY  CHART 


Grade 

Wt. 

St’d. 

100 

99.8 

99.6 

99.4 

99.2 

99.0 

98.8 

98.6 

98.4 

98.2 

A 

36 

45 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

38 

50 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

42 

55 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

46 

60 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

52 

70 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

58 

80 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

B 

f 

60 

90 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

70 

110 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

80 

125 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

C 

30 

40 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

35 

45 

5 

^  6 

7 

8 

9 

10 

11 

12 

13 

14 

37 

50 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

40 

60 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

44 

70 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

50 

75 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

D 

30 

30 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

34 

35 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

36 

37 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

42 

42 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

50 

50 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

E 

. 

. 

30 

45 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

33 

50 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

35 

70 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

38 

100 

10 

11 

12 

13' 

14 

15 

16 

17 

18 

19 

40 

110 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

42 

120 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

45 

130 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

F 

38 

50 

5 

6 

7' 

8 

9 

10 

11 

12 

13 

14 

42 

60 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

46 

70 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

48 

90 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

Note.  Standard  given  in  seconds 

Figures  to  right  of  Standard  Column  indicate  seconds  over  or  under  Standard  for  each 
weight 

Standard  in  seconds 


Fig.  202 
484 


TB.  401 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  485 

hour ;  production  per  stone ;  tons  per  stone ;  pounds  per  cord  of 
wood  consumed;  freeness  of  stock;  hours  down;  total  efficiency. 
The  freeness  of  ground  wood  stock  is  obtained  by  using 


Scott’s  Freeness  Tester  and  designates  the  nature  of  the  stock 
whether  slow,  free  or  shievey. 

All  of  this  data  not  only  serves  as  a  systematic  check  upon 
mill  operations  and  product  made  but  also  when  presented  in 
the  right  spirit  serves  as  an  incentive  to  the  men. 

Somewhat  along  the  same  lines,  the  Department  of  Physical 


PENALTY  FOR  REJECTED  PAPER 

BASED  ON  PERCENT  OF  REJECTED  PAPER  FROM  TOTAL  PRODUCTION  FOR  THE  WEEK 


%  Rejected  Paper  %  Efficiency 


.25 

99.5 

.50 

99.0 

.75 

98.5 

1.00 

98.0 

1.25 

97.5 

1.50 

97.0 

1.75 

96.5 

2.00 

96.0 

2.25 

1 

95.5 

2.50 

95.0 

2.75 

94.5 

3.00 

• 

94.0 

3.25 

93.5 

3.50 

93.0 

3.75 

4.00 

92.5 

92.0 

4.25 

91.5 

4.50 

91.0 

4.75 

90.5 

5.00 

90.0 

5.25 

89.5 

5.50 

89.0 

5.75 

88.5 

6.00 

88.0 

6.25 

6.50 

6.75 

87.5 

87.0 

86.5 

TlM.i 


Fig.  204. 


486 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  487 


z. 

o 


LU 

a. 

c/l 

Z 


s 

D. 

< 

Q. 


Fig.  205. 


Tests  traces  the  workings  of  the  sulphite  mills  as  shown  in  Figure 
207  which  includes  the  following : — total  production ;  per  cent 
screenings ;  quality  of  pulp ;  average  filling  time ;  quality  of  cook¬ 
ing  acid;  per  cent  reclamation;  efficiency  of  chips;  sulphur  con¬ 
sumption  ;  cooking  time ;  production  per  digester ;  temperature  of 


GROUND  WOOD  MILLS  DAILY  EFFICIENCY  CHART 


488 


UNION  BAG  &  PAPER  CORPORATION 
SULPHITE  MILLS 

DAILY  EFFICIENCrCHART  bate  xo,  /<?*». 


M 

J 


S  s  s 

■So 


M2 


It 


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"?a 


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£!?<r 


o  3 

CT)  ^ 


c^ 


— o 


be 


n 

5 


489 

♦ 


Fig.  207. 


490  MODERN  PULP  AND  PAPER  MAKING 

water;  temperature  of  gas;  temperature  of  acid  to  digester; 
moisture  in  chips;  hours  down;  causes;  total  efficiency. 

The  above  concludes  the  general  routine  work  of  the  Depart- 


JULPHiTC  Mill  ^  „ 

liiCiic/)sc  Co)7  r.n  Coup  c  Uoop  Pul  rc  Punmno  Pllllp  Woop  Tmpouch  BmHIN6  PnuMi 

ron^FLCML  BuLPHITC 


mCojT...  CoRPr-'  LuBFUcmrs^OM 

\coi7 F"  Conp  1“ PowLR -Pun  B/tPMmo  DnuMS  40Z 

\COiTF"  COFIPI-POWLP  UlLPi-  Woop  flOOMiOC) 


COSTp^'COPP  ft  OrLPPTL  TUMBLLn-5\S./6  7 


C03T F-’  COUP  u,  WPP  OPCMTIOm  <S.ZI6 


COiTp"  coup  /”  WOOP  POOM  OPLPPTIOnS  (CHIPPmO.-')  ^JZ6 


C05Tf-  cone- HPNPLinc  wooPi’—PiLLiF:,-CHiPPtn(D/inHiiicecpuciiPi-t.Sl^.l6 7  Jfiyc p) 


r.osTF-Copp  I-'  woop  opEnPTiopi t'--  Pill  chipplh  1.003  (f.iB7 Incpl/islT 


5^ 


Fig.  2o8. 


ment  of  Physical  Tests  in  conjunction  with  the  Bureau  of  Chem¬ 
istry.  Along  with  this  work  special  mill  tests  are  run  in  order  to 
determine  efficient  cost,  production  and  quality  standards.  Fig- 


Fig.  209. 


ures  208  to  215  inclusive  show  Graphic  Analyses  of  some  of 
these  various  tests.  Moreover,  competitors’  papers  are  constantly 
tested  in  conjunction  with  one’s  own  and  samples  are  filed  away 
under  both  bad  and  good  storage  conditions  in  order  to  ascer¬ 
tain  relative  per  cent  deterioration  of  the  various  grades  of  paper. 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  491 

In  testing  one’s  own  grades  for  deterioration  of  course  it  is  essen¬ 
tial  to  have  all  characteristics  and  data  connected  with  the  making 
of  that  sheet,  in  order  that  the  test  may  be  of  any  value.  By 
this  means  quality  of  material  is  often  proved  to  be  below  stand- 


Fig.  211. 


ard  when  stored  under  both  poor  and  normal  conditions,  or  again 
it  may  result  in  some  change  in  the  process  of  manufacture  in  an 
attempt  to  cure  the  evil. 

The  work  outlined  above  is  not  of  a  very  technical  nature  and 
one  trained  chemist  assisted  by  several  conscientious  helpers  can 


Fig.  212. 


(•'iju/tirr  a'’*(3i"iRT  ^  ^  Quart 


Fig.  213. 


■  •  i 


492 


TESTING  OF  TAPER  AND  PAPER  AEITERIAES  493 

carry  out  this  program  to  complete  satisfaction.  In  connection 
with  the  Physical  Tests  Department,  a  good  practical  paper  maker 
must  be  included  in  its  personnel  in  order  to  pass  judgment  on 
various  paper  qualities  that  are  not  shown  up  by  any  mechanical, 


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chemical,  or  physical  tests.  By  the  maintenance  of  such  a  de¬ 
partment,  properly  supervised,  the  security  obtained,  not  only 
for  the  good  will  of  the  company,  but  for  all  concerned,  serves 
as  an  insurance  or  protection  to  all  buyers.  Of  course,  the  system 
is  not  infallible,  but  it  does  minimize  causes  for  error  and  ship¬ 
ment  of  inferior  quality  of  goods,  as  well  as  wastefulness  in 
manufacturing. 


MODIiR\^  PULP  AND  PAPER  MAKING 


4'J4 

General  Testing  of  Supplies. 

Very  little  reliable  information  can  be  obtained  from  sales 
agents  for  various  supplies  for  each  agent  has  his  own  interests 
at  stake,  and  it  is  bis  business  to  promote  the  sale  of  his  material. 


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Mg.  215, — Chari  showing  percent,  time  down,  percent,  time  loading  cutters 
and  percent,  actual  time  cutters. 


The  necessity  for  testing  therefore  becomes  apparent.  In  a 
large  number  of  cases  the  best  method  is  to  put  the  article  to 
practical  use  and  keep  accurate  record  of  its  service  as  in  the 
case  of  wires,  felts,  etc. 

In  other  cases  we  have  chemical  testing;  also  physical  test¬ 
ing  as  strength  of  twine,  belting,  etc. 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  495 

Meaning  of  the  Word:  Testing,  in  the  broadest  sense,  means 
any  method  of  procedure  with  the  object  of  ascertaining  facts 
about  the  thing,  for  example : 

A  car  of  coal  is  weighed  in  order  to  ascertain  its  weight  more 
or  less  than  the  weight  invoiced;  this  is  testing  its  weight. 

If  a  piece  of  clay  is  placed  in  the  mouth  in  order  to  ob¬ 
serve  how  it  feels  between  the  teeth;  this  is  testing  its  grit. 

If  several  felts,  wires,  etc.,  are  used  exactly  under  the  same 
conditions  and  a  record  kept  to  see  which  gives  the  best  service ; 
this,  also,  is  testing. 

Weighing:  The  invoice  weights  of  all  kinds  of  material 
should  be  checked  by  weighing  on  accurate  scales. 

Testing  Scales:  All  scales  should  be  periodically  tested  as 
to  the  accuracy  of  their  calculations. 

The  principle  upon  which  paper  is  weighed  is  as  follows : 
one  pound  =  16  ounces.  30  pounds  therefore  30  x  16  =  480 
ounces.  If,  therefore,  the  count  basis  is  480  sheets,  one  sheet  of  a 
30  pound  paper  will  weigh  exactly  i  ounce  so  that  a  test  weighing 
exactly  i  ounce  be  placed  upon  the  scales  instead  of  a  sheet  of 
paper  it  will  register  exactly  30  pounds  on  the  480  count.  On  the 
500  count  basis  one  sheet  of  a  30  pound  paper  will  weigh  480-500 
of  one  ounce  or  96-100  of  an  ounce. 

When  test  weights  of  exactly  i  ounce  are  placed  upon  these 
scales,  one  after  another  they  should,  therefore,  register  as  fol¬ 
lows  ; 

Count  12  3  45  Oz. 

480  30  60  90  120  150 

500  31-25  62.50  93-75  125  156-25 

Measuring:  Measuring  the  dimensions  of  a  thing  is  also 
a  testing  process.  Measuring  is  sometimes  connected  with 
weighing  as,  for  example,  in  the  case  of  twine,  exactly  i  pound 
may  be  weighed  and  measured  so  as  to  calculate  the  weight  per 
100  feet  and  thus  get  comparative  weights  for  different  makes  or 
brands. 

Counting  is  another  method  as  in  counting  the  mesh  of  a 
wire  with  a  magnifying  glass. 

Testing  of  Belting:  The  various  grades  of  belting  depends 
to  a  large  extent  upon  the  composition  of  the  friction  used  in  their 
manufacture. 

The  highest  grade  of  pure  rubber  gives  the  strongest  and  most 
durable  friction  while  “recovered  rubber”  and  inferior  com¬ 
positions  give  inferior  tests  and  deteriorate  rapidly. 

To  test — Cut  3  strips  smoothly  and  evenly  i  in.  in  width, 
separate  the  ply  for  i  inch  or  2  inches  by  means  of  a  knife  in 
order  to  separate.  Make  a  mark  slightly  beyond  the  point  of 
separation  and  hang  the  strip  by  means  of  a  clamp,  etc. 

Let  the  strip  hang  naturally.  Pull  with  the  hand  till  you 


496  MODERN  PULP  AND  PAPER  MAKING 

reach  the  separation  mark  and  take  the  time  with  a  watch. 
The  separation  should  not  average  more  than  i  inch  per  minute, 
the  average  of  the  three  strips  being  taken. 

Some  grades  will  only  stand  5  or  6  pounds  and  are  inferior; 
others  will  stand  weights  of  19  or  20  pounds. 

Comparisons  may  be  made  by  using  the  same  weight  (14 
pounds)  for  all  belts  and  calculate  the  rate  of  separation.  Poor 
belting  will  separate  quick  under  a  14  pound  weight.  By  a  sys¬ 
tematic  examination  of  every  roll  valuable  information  can  be 
obtained  as  to  different  makes  and  brands. 

The  Drying  Oven. 

Tests  for  quantity  of  water  or  moisture  in  anything  are 
among  the  most  important  class  of  testing,  and  a  drying  oven 
is  an  essential  part  of  the  equipment  in  every  mill.  These  ovens 
may  be  either  steam  or  electric.  Good  dealers  in  laboratory  sup¬ 
plies  carry  both  kinds  and  can  suggest  a  suitable  type. 

Among  the  tests  for  water  or  moisture  contained  in  materials 
we  may  mention  the  following: 

Moisture  of  Pulp:  Pulp  both  chemical  and  mechanical  pulp 
such  as  sulphite,  and  soda  and  in  fact  any  paper  making  pulp 
is  tested  for  moisture  and  water  by  taking  a  sample,  weighing 
it  accurately  bone  dry  and  again  weighing  it.  The  loss  in  weight 
gives  the  amount  of  moisture  or  water  in  it  and  from 
the  weights  observed  the  percentages  of  water  or  moisture  and 
the  bone  dry  pulp  are  easily  calculated. 

It  is  ordinarily  assumed  that  paper  pulp  after  being  dried 
bone  dry  and  then  left  exposed  to  the  air  will  absorb  10  per  cent 
of  its  weight  of  moisture  from  the  atmosphere. 

This  figure  10  per  cent  is  a  fairly  approximate  average,  but, 
of  course,  the  true  amount  of  moisture  absorbed  from  the  air 
depends  on  the  dryness  or  dampness  of  the  weather  which  is 
constantly  changing.  At  times  when  the  air  is  very  dry  a  bone 
dry  pulp  will  not  absorb  anything  like  10  per  cent  moisture 
while  at  other  times  when  the  atmosphere  is  very  moist,  it  will 
absorb  considerably  more  than  10  per  cent.  Under  ordinary 
conditions  during  the  year  it  is  nearer  to  9  per  cent  than  to 
10  per  cent,  but  this  again  varies  with  the  locality,  for  one  locality 
during  the  year  is  different  from  another. 

Calculating  Dry  Pulp:  In  our  opinion  the  true  basis  for 
estimating  the  percentage  of  air  dry  material  is  the  bone  dry 
weight,  but  it  makes  no  difference  what  percentage  is  added 
to  this  as  long  as  the  same  percentage  is  uniformly  adopted. 
10  per  cent,  is  as  satisfactory  as  any  although  it  may  not  rep¬ 
resent  the  actual  percentage  of  moisture  absorbed  in  the  ma¬ 
jority  of  cases. 

Moisture  in  Paper:  The  percentage  of  moisture  in  paper 
can  also  be  readily  determined  by  means  of  a  drying  oven.  This 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  497 

is  a  very  important  test,  being  of  much  value  in  enabling  one 
to  regulate  the  drying  of  paper  on  a  machine. 

Newspaper  when  overdried  is  brittle  and  unsatisfactory,  while 
if  too  much  moisture  is  left  in  it  the  calendering  produces  a 
mottled  smutty  appearance,  but  such  paper  takes  a  superior 
finish  to  that  which  has  been  overdried. 

As  is  well  known,  the  best  results  are  obtained  when  the 
paper  is  run  as  damp  as  possible  without  getting  mottled  or 
smutty  in  appearance. 

Experiments  have  shown,  in  the  case  of  newspaper,  that  the 
best  degree  of  moisture  is  between  9  per  cent  and  ii  per  cent,  on 
the  average,  10  per  cent. 

This  is  the  percentage  which  is  added  to  “bone  dry  pulp” 
to  convert  it  into  air  dry  weight  upon  which  calculations  as 
to  “production”  and  loss  of  raw  material  are  based. 

If  paper  is  run  (as  is  frequently  the  case)  with  only  7  per 
cent  of  moisture  in  it  and  calculations  are  based  upon  air  dry 
pulp  containing  10  per  cent  of  moisture,  there  is,  of  course, 
a  loss  of  raw  material  due  to  the  paper  being  run  too  dry. 

By  running  the  paper  damper  not  only  is  there  a  gain  in  the 
production  but  the  quality  of  the  paper  that  is  run  on  the  paper 
machine  is  more  or  less  greatly  improved. 

Another  bad  effect  of  overdrying  lies  in  the  fact  that  over- 
dried  paper  will  absorb  moisture  from  the  atmosphere  and  in¬ 
crease  in  weight  so  that  if  a  sample  of  paper  fresh  from  the 
machine  weighs  33  pounds  it  might  readily  take  up  sufficient  mois¬ 
ture  to  be  34  pounds  when  tested  by  the  customer  and  furnish 
grounds  for  complaint  as  to  overweight. 

The  best  method  of  testing  the  product  of  a  paper  machine 
for  moisture  is  to  take  as  large  a  sample  as  the  scales  can  con¬ 
veniently  weigh,  weigh  the  sample  immediately  and  mark  the 
weight  on  it.  Then  place  it  in  the  drying  oven  and  allow  it  to 
remain  until  bone  dry  when  it  is  again  immediately  weighed 
and  the  loss  in  weight  calculated  into  percentage.  If  less  than 
10  per  cent  it  shows  that  the  paper  has  been  run  too  dry  on 
the  machine.  In  case  of  many  papers,  such  as  heavy  wrappers, 
much  more  than  10  per  cent  of  water  can  be  left  in  the  paper.  In 
all  cases  a  sample  of  such  paper  will  dry  out  and  lose  weight 
upon  exposure  to  the  atmosphere. 

Moisture  in  Clay:  The  drying  oven  is  also  a  convenient 
and  accurate  appliance  for  testing  the  moisture  of  many  other 
substances.  The  best  method  for  testing  clay  for  moisture  is  as 
follows : 

A  tin  pan  is  weighed  accurately  and  its  weight  recorded. 
It  is  then  filled  level  with  clay  and  weighed  again ;  the  difference 
in  weight  is  the  weights  of  the  clay  taken  for  test.  The  pan 
is  now  placed  in  an  oven  until  the  clay  is  bone  dry  and  again 
weighed.  The  loss  in  weight  is  due  to  water  or  moisture  and  is 
calculated  into  percentage. 


498  MODERN  PULP  AND  PAPER  MAKING 

In  this  connection  it  may  be  safe  to  state  that  the  clay  is 
a  material  which  not  only  contains  water  in  the  form  of  damp¬ 
ness  or  moisture  but  also  contains  chemically  combined  water 
wbich  cannot  be  expelled  by  drying  in  an  oven. 

This  water  forms  a  part  of  the  clay  and  is  not  driven 
off  by  the  heat  of  the  drying  oven  or  by  the  dryness  of  a 
paper  machine  but  remains  in  the  clay  in  the  dried  paper 
even  if  the  paper  is  dried  “bone  dry.”  If  some  clay  is  put  in  a 
crucible  and  submitted  to  furnace  heat,  as  in  burning  brick,  this 
chemically  combined  water  is  expelled  and  the  clay  becomes 
hard  like  a  brick  and  will  no  longer  dissolve  or  “break  down” 
into  a  fine  powder  when  stirred  with  water.  If  pulverized, 
each  small  particle  is  hard  and  gritty  and  not  soft  and  sticky  like 
an  unburnt  clay  is.  It  is  tins  fact  that  renders  clay  so  valuable 
in  the  manufacture  of  pottery.  The  combined  water  not 
being  driven  off  to  the  slightest  extent  in  the  process  of  manu¬ 
facture  of  paper  it  does  not  therefore  enter  into  considera¬ 
tion  at  all  in  making  moisture  tests.  All  clay  is  more  or  less 
damp  and  it  is  simply  the  extent  of  the  dampness  which  is  of 
importance  which  is  easily  determined  by  drying  in  an  oven 
as  pulp  or  paper  is  dried. 

Whatever  percentage  of  dampness  or  moisture  clay  contains 
is  so  much  loss  for  it  is  bone  dry  when  the  paper  has  passed 
over  the  dryers  in  the  machine. 

The  fibres  of  paper  or  pulp  when  bone  dry  suck  up  or 
absorb  moisture  from  the  atmosphere,  but  dry  clay  may  lie 
exposed  to  the  atmosphere  without  absorbing  any  noticeable 
amount  of  moisture. 

If,  therefore,  lOO  pounds  of  damp  clay  containing  lo  per  cent 
moisture  are  furnished  to  a  ton  of  paper  the  lo  per  cent  of  mois¬ 
ture  in  the  clay  is  all  dried  out  and  only  90  pounds  of  actual  clay 
have  been  furnished  in  reality. 

In  testing  the  percentage  of  clay  by  paper  all  of  the  above 
features  of  clay  must  be  taken  into  consideration  and  a  sample 
of  the  clay  itself  must  be  tested  as  well  as  the  sample  of  the 
paper  used  in  order  to  obtain  tbe  correct  and  true  results. 

Testing  for  Retention  of  Clay:  See  under  “Clay”  in  Chap¬ 
ter  XII. 

Moisture  in  Ahun,  Soda  Ash,  Lime,  etc.:  There  are  certain 
materials  which  absorb  water  or  moisture  from  the  atmosphere 
or  which  contains  water  chemically  combined  with  the  other 
constituents  of  the  substance  in  such  forms  of  combination  that 
it  cannot  be  dried  out  again  by  heating  in  a  drying  oven. 

Alum,  for  example,  contains  a  large  amount  of  water  which 
cannot  be  dried  out  of  it  even  at  high  temperatures  without  de¬ 
composing  the  alum  itself.  At  a  high  heat  the  alum  melts  or 
fuses  without  losing  much  water  and  if  heated  to  a  still  higher 
degree,  so  as  to  drive  off  water,  the  alum  is  decomposed  and  the 
sulphuric  acid  is  also  driven  off.  There  is,  therefore,  no  method 


TESTING  OF  PAPER  AND  PAPER  MATERIALS  499 

for  estimating  directly  the  quantity  of  water  in  alum.  The 
percentages  of  all  other  ingredients  can  be  determined  ac¬ 
curately  by  tests  and  the  water  by  ditference. 

Lime  also  absorbs  moisture  and  carbonic  acid  from  the  at¬ 
mosphere  and  becomes  more  or  less  “air  slacked.”  Such  mois¬ 
ture  and  acid  cannot  be  driven  off  from  tbe  air  slacked  lime  by 
heating  in  an  oven,  but  it  can  be  accurately  determined  by  in¬ 
tense  ignition  of  the  lime,  as  no  decomposition  takes  place  and 


Courtesy:  Mellon  Inst,  of  Industrial  Research.  Pittsburgh.  Pa. 

Fig.  215a. — Drum  tester  used  for  determining  strength  of  fibre-board 
containers.  The  drum  is  rotated  until  the  container  breaks  and  the 
number  of  revolutions  is  recorded. 

by  ignition  and  air  slacked  lime  is  brought  back  to  the  original 
condition  of  the  freshly  burned  lime. 

Soda  ash  like  lime  absorbs  moisture  from  the  air  and  in¬ 
creases  in  weight,  but  the  water  absorbed  can  only  be  driven  off 
completely  by  heating  to  a  dull  red  heat.  Some  can  be  driven  off 
in  a  drying  oven  but  not  all  of  it. 

Moisture  in  Coal:  Coal  can  be  dried  bone  dry  in  a  drying 
oven.  Many  times  the  coal  delivered  is  quite  wet  and  if  cars 
are  weighed  a  test  for  moisture  is  important  to  decide  whether 
or  not  the  full  dry  weight  of  the  coal  is  delivered. 

In  conducting  boiler  tests  the  moisture  in  the  coal  used  must 
also  be  determined  and  allowance  made  therefore. 

Testing  Stock:  In  determining  the  capacity  of  chests,  con¬ 
centration  of  liquid  stock,  etc.,  it  is  often  desirable  to  test  how 


500  MODERN  PULP  AND  PAPER  MAKING 

much  dry  stock  the  liquid  contains  per  cubic  foot.  This  is 
best  accomplished  as  follows : 

Record  the  weight  of  a  pie  pan  on  the  scales.  Take  exactly 
I  quart  of  the  liquid  stock  by  means  of  an  accurate  quart  measure. 
Pour  this  into  a  piece  of  cotton  cloth  and  squeeze  out  as  much 
of  the  water  as  possible.  Transfer  the  stock  from  the  cloth 
to  the  pie  pan.  Repeat  this  until  the  pan  is  about  full  recording 
the  number  of  quarts  necessary. 

In  the  case  of  thick  liquid  stock  one  or  two  quarts  may  be 
enough  while  with  thin  stock  a  number  of  quarts  must  be  taken 
to  get  a  pan  full.  Care  must  be  taken  that  no  stock  is  lost  dur¬ 
ing  the  operation. 

The  pie  pan  of  wet  stpck  is  then  placed  in  the  drying  oven 
and  allowed  to  remain  until  it  is  bone  dry.  When  it  is  taken  out 
and  weighed.  It  is  well  to  put  in  again  then  weigh  again,  so 
that  it  is  perfectly  dry.  The  bone  dry  weight  is  calculated  into 
air  dry  weight  as  usual  by  dividing  by  90  and  multiplying  by 
100.  This  gives  the  air  dry  weight  of  stock  in  the  number  of 
quarts  measured  out  for  the  test,  from  which  the  weight  in  one 
quart  is  calculated. 

The  weight  in  one  quart  multiplied  by  4  gives  the  weight  in 
a  gallon.  The  weight  in  one  quart  x  30  gives  the  weight  in  one 
cubic  foot  as  there  are  30  quarts  to  a  cubic  foot  (exact  figures 
29.922  quarts). 


XVIII.  Paper  Defects;  their  Cause  and  Cure. 

Like  all  commercial  products  paper  is  liable  to  possess  cer¬ 
tain  defects  which  cause  trouble  for  the  printers  and  other 
users  of  paper.  It  is.  incumbent  upon  a  mill  which  wishes  to 
hold  the  good  will  of  the  consumer  to  do  everything  possible 
to  reduce  the  percentage  of  defective  product  to  a  minimum. 

Fortunately,  most  of  these  defects  fall  into  well  defined 
classifications  and  the  cause  of  them  is  well  known  in  most  cases 
and  can  be  prevented  by  greater  care  on  the  part  of  the  help 
and  by  the  improvement  of  mechanical  and  chemical  processes. 

Slime  Spots:  These  appear  in  paper  as  hard,  shiny,  dis¬ 
colored  patches.  They  are  caused  by  accumulations  of  slime 
forming  somewhere  in  the  preparation  of  the  stock  and  getting 
onto  the  wire.  Dirty  beaters,  dirty  piping,  dirty  chests,  head- 
boxes,  etc.,  are  sure  to  produce  this  evil.  It  can  be  corrected 
by  having  all  such  equipment  so  designed  that  there  is  little 
opportunity  for  slime  to  accumulate,  and  then  having  it  inspected 
at  sufficiently  frequent  intervals  that  it  will  be  thoroughly  washed 
out  when  necessary.  When  a  beater  or  chest  is  flushed  out 
to  remove  slime  the  wash  water  should  not  be  sent  to  the  save- 
all  system,  but  should  go  direct  to  the  main  sewer,  otherwise 
the  slime  will  just  remain  in  the  system  and  build  up  in  total 
volume.  The  screens  used  with  the  paper  machines  are  the  worst 
offenders  as  to  slime  in  the  whole  mill.  The  causes  leading  to 
the  accumulation  of  slime  in  these  screens  and  the  steps  to  be 
taken  to  prevent  it  have  been  discussed  already  in  connection 
with  the  section  on  screens  in  the  chapter  on  the  machine  room, 
so  it  is  not  necessary  to  do  more  than  refer  the  reader  to  that 
place.  The  discharge  pipe  leading  from  the  screens  is  another 
bad  place,  which  should  be  watched  for  slime. 

In  general  slime  can  largely  be  prevented  by  taking  certain 
precautions  when  the  equipment  is  installed.  Care  should  be 
taken  to  avoid  all  sharp  corners  in  equipment  and  piping  in  which 
stock  is  to  be  handled.  Such  corners,  when  unavoidably  present, 
should  be  filled  in  with  fillets.  Chests  should  be  so  designed  that 
the  currents  created  by  the  agitators  reach  every  part  of  the 
chest,  leaving  no  dead  pockets  in  which  the  stock  can  stagnate 
and  slime  collect.  All  surfaces  in  contact  with  stock  should  be 
well  finished  and  smooth.  Roughness  and  irregularities  afford 
lodging  places  for  small  particles  which  eventually  grow  into 
blobs  of  slime,  fall  off  and  pass  into  the  stock  furnished  to  the 
machine.  The  first  step  in  preventing  slime  is  to  build  all  equip¬ 
ment  in  accordance  with  the  above  precautions.  The  second  is 

SOI 


MODERN  PULP  AND  PAPER  MAKING 


502 

to  have  frequent  and  regular  wash-ups  of  all  such  equipment  to 
get  rid  of  what  slime  will  inevitably  form. 

Hair  Cuts:  When  a  fibre  of  wool  or  sisal  or  some  other 
harsh  material  gets  into  the  sheet  it  will  cut  the  paper  as  it  goes 
through  the  calendar  stack.  This  causes  a  great  deal  of  trouble 
if  the  paper  is  being  used  for  printing,  and  in  fact  for  any  use. 

Tbe  sisal  fibres  are  much  the  worst.  They  get  into  stock  on 
account  of  sisal  twine  or  rope  being  used  for  bundling  in  the 
finishing  room.  Pieces  of  this  material  get  swept  up  with  the 
broke  and  as  the  treatment  of  broke  in  the  beater  is  of  short 
duration  the  fibre  goes  into  the  stock  in  almost  its  original  con¬ 
dition.  Sometimes  sisal  gets  into  stock  from  bundles  of  pulp. 
One  way  to  prevent  this  is  not  to  allow  the  use  of  sisal  twine. 
The  second  precaution  is  to  see  that  no  sweepings  from  the  fin¬ 
ishing  room  floor  are  put  into  the  bin  with  the  broke. 

The  wool  fibres  come  chiefly  from  the  washing  of  new  felts, 
or  from  felts  which  have  been  newly  napped.  All  wash  water 
from  this  source  should  be  run  directly  to  the  main  sewer  and 
under  no  circumstances  allowed  to  go  to  the  save-alls,  which 
would  lead  to  wool  fibres  in  the  white  water  and  thus  getting 
back  into  the  stock. 

There  are  certain  other  fibres  which  get  into  the  stock  from 
sweepings  and  miscellaneous  causes,  but  according  to  an  investi¬ 
gation  of  the  matter  made  by  a  large  printing  company,  more 
than  three-quarters  of  all  fibres  causing  hair-cuts  in  paper  are 
either  sisal  or  wool  fibres.  This  investigation  was  made  by  exam¬ 
ining  all  the  offending  fibres  with  a  microscope  and  comparing 
them  with  standard  slides  showing  known  fibres. 

Calender  Cuts:  Calender  cuts  are  slits  extending  horizon¬ 
tally  across  the  sheet,  the  paper  along  the  line  of  the  slit  being 
glazed  and  discolored.  These  cuts  will  invariably  cause  the 
paper  to  break  when  used  in  a  press  or  in  any  automatic  machine. 
They  are  the  result  of  careless  supervision  of  the  calenders. 
For  instance,  if  anything  makes  the  sheet  go  over  from  the 
dryers  to  the  calender  slack,  there  will  be  sure  to  be  calender 
cuts.  The  sheet  should  go  over  just  as  tight  as  possible  without 
straining  it.  Improper  lubrication  of  the  calenders  may  cause 
this.  Another  cause  would  be  slipping  of  the  belt  driving  the 
calender.  If  the  calender  rolls  are  crowding  it  is  sure  to  pro¬ 
duce  calender  cuts.  Also  if  the  sheet  is  a  little  thicker  on  one 
edge  than  on  the  other  it  will  wallow  as  it  goes  down  through 
the  calender  and  this  again  will  cause  these  cuts.  The 
remedy  in  the  case  of  each  of  the  above  causes  of  calender  cuts 
is  obvious  and  it  only  requires  watchfulness  and  suitable  regula¬ 
tion  to  eliminate  these  defects. 

Calender  Spots:  These  are  due  to  little  specks  of  paper  that 
get  on  the  sheet  as  it  goes  through  the  calender  stack.  They 
bruise  the  paper,  glazing  it  slightly  at  the  same  time.  These  little 
scabs  are  largely  due  to  wet  ends,  etc.,  going  through  the  calen- 


PAPER  DEFECTS;  THEIR  CAUSE  AND  CURE  503 

der  stack,  after  which  the  scabs  of  paper  adhere  to  the  rolls  and 
go  around  again  and  again.  Good  calender  doctors,  well  looked 
after,  will  do  much  to  prevent  this  trouble,  but  it  is  bound  to 
happen  at  times  in  spite  of  all  precautions.  However,  in  the 
case  of  an  occurrence  of  this  kind  taking  place,  the  stack  ought 
to  be  well  cleaned  before  the  paper  is  put  through  again. 

Crush  Marks:  Crush  marks  are  distinguished  by  a  curdled 
appearance  in  the  paper.  These  marks  are  quite  distinctive  in 
appearance  and  cannot  well  be  mistaken  for  any  other  form  of 
defect  once  they  are  recognized.  The  cause  of  these  marks  is 
that  the  felt  fills  up  with  clay  and  other  filler  as  well  as  with 
fine  fibre.  The  water  cannot  get  through  the  felt  at  this  point 
and  consequently  is  squeezed  out  as  the  felt  and  the  paper  pass 
through  the  press,  spoiling  the  surrounding  portions  of  the 
sheet.  The  cure  for  this  is  simply  to  keep  the  felts  clean.  De¬ 
tailed  instructions  on  the  care  of  felts  will  be  found  in  the  chap¬ 
ter  on  the  machine  room. 

Dandy  Crush  Marks:  These  marks  also  have  a  curdled  ap¬ 
pearance,  but  differ  from  the  ordinary  felt  crush  in  not  being 
localized  but  rather  spreading  over  the  whole  surface  of  the 
sheet.  These  marks  are  caused  by  the  too  liberal  use  of  water 
with  the  dandy  roll,  the  roll  wading  in  water  which  cannot  get 
through  the  sheet  in  the  usual  manner.  The  best  remedy  is  to 
use  less  water  and  more  suction  back  of  the  dandy. 

Coucher  Crush  Marks:  Coucher  crush  marks  are  coarser 
than  dandy  crush  marks  and  there  are  wide  sepaations  between 
the  lumps  of  stock.  These  are  caused  by  the  suction  boxes  fail¬ 
ing  to  take  sufficient  water  out  of  the  sheet,  which  may  be  due  to 
too  liberal  use  of  water,  to  too  slow  stock  or  to  imperfect 
operation  of  the  suction  boxes  themselves,  such  as  inadequate  suc¬ 
tion.  It  may  also  be  due  to  the  machine  running  too  fast  for  the 
weight  of  paper  being  made.  To  prevent  these  marks  it  is  ad¬ 
visable  to  find  out  which  of  the  above  causes  is  responsible  and 
then  adjust  the  operation  of  the  machine  so  as  to  correct  the 
fault. 

Dandy  Blisters:  These  blemishes  look  like  a  blister  that  has 
been  raised  up  on  the  surface  of  the  paper  and  then  pressed 
down,  causing  a  number  of  concentric  wrinkles.  The  chief  cause 
of  these  marks  is  a  dandy  roll  that  is  filled  up  in  places.  This  is 
especially  so  if  the  sheet  is  pretty  dry  under  the  dandy.  A 
dandy  roll  that  will  run  without  trouble  if  supplied  with  a  liberal 
amount  of  water  will  start  to  pick  up  if  the  water  supply  is 
decreased.  The  real  cure  for  this  trouble  is  to  take  the  dandy 
off  and  clean  it  as  described  in  the  chapter  on  the  machine  room. 
However,  some  temporary  relief  may  be  secured  by  giving  a  little 
more  water  and  this  trouble  can  be  lessened  by  keeping  the  show¬ 
ers  used  in  connection  with  the  dandy  working  evenly  and  per¬ 
fectly. 

Bubble  Marks:  When  stock  shows  a  tendency  to  foam,  bub- 


MODERN  PULP  AND  PAPER  MAKING 


504 

bles  will  frequently  form  on  the  wire  which  will  break  when  they 
come  over  the  suction  boxes.  The  spot  where  the  bubble  was, 
will  be  deficient  in  actual  fibres  and  consequently  there  will  be  a 
thin  spot  on  the  paper.  These  marks  are  usually  quite  perfectly 
circular,  in  which  respect  they  differ  from  other  marks  which 
are  usually  irregular,  and  they  are  not  noticeably  curdled  or 
wrinkled.  With  light  tinted  papers  the  bubbles  will  leave  a  dis¬ 
tinct  ring  of  concentrated  color  when  they  break.  A  steam 
shower  or  compressed  air  shower  running  across  the  sheet  some 
distance  back  of  the  dandy  will  usually  break  these  bubbles  up. 
This  shower  should  be  sufficiently  far  back  of  the  suction  boxes 
that  the  shake  will  have  a  chance  to  fill  up  the  places  left  thin 
by  the  breaking  of  the  bubbles  before  the  sheet  passes  over  the 
suction  boxes. 

Eroth  Marks:  These  marks  are  due  to  large  patches  of 
froth  or  foam  forming  as  the  stock  flows  onto  the  wire.  Some¬ 
times  a  paper  machine  will  be  used  at  a  much  lower  speed 
than  the  average  of  which  such  a  machine  is  capable,  owing  to 
a  variation  in  the  weight  of  the  paper  being  produced.  The 
pump,  however,  is  driven  by  a  constant  speed  line  and  in  com¬ 
parison  with  the  machine  is  racing  at  a  very  high  speed,  churn¬ 
ing  the  stock  up  and  causing  it  to  foam.  As  the  distance  from 
the  pump  to  the  wire  is  small,  the  stock  will  go  on  the  wire  foam¬ 
ing,  and  this  condition  will  be  accentuated  if  there  is  anything 
in  the  stock  peculiarly  conducive  to  the  cause  of  the  foam.  This 
can  largely  be  avoided  by  introducing  a  drive  for  the  pump,  on  a 
machine  which  is  to  be  used  at  a  variety  of  speeds,  which  will 
permit  of  the  speed  of  the  pump  being  varied. 

A  good  shower  right  over  the  apron  and  slices  will  usually 
break  down  all  the  foam,  but  if  foam  persists  in  spite  of  this  a 
little  kerosene  may  be  added  to  the  stock  in  the  beaters,  or 
dropped  into  the  pump  box — 2  or  3  drops  a  minute.  This  tends 
to  keep  foam  down  by  forming  a  thin  film  on  the  surface  of  the 
stock.  The  shower  should  have  i  /16-inch  openings  and  a  good 
pressure  so  as  to  create  a  fine  needle  stream.  Alum  will  also 
tend  to  decrease  the  foam  in  most  cases,  although  there  are  some 
cases  where  alum  will  positively  increase  foam,  for  instance,  when 
certain  pigments  are  used  which  react  with  alum  so  as  to  produce 
a  gas. 

Blemishes  Caused  by  Drops  of  Water:  Steam  will  condense 
on  the  roof  of  the  machine  room  and  drops  of  water  will  drip 
onto  the  wire.  These  marks  are  easily  distinguished  from  bub¬ 
ble  marks  as  they  are  irregular  in  outline  although  roughly  cir¬ 
cular.  Sometimes  the  drop  falls  with  sufficient  force  to  make 
not  only  a  mark  but  a  hole.  The  cure  for  this  evil  is  to  have 
a  ventilation  system  that  will  prevent  condensation  taking  place. 
This  is  dealt  with  at  length  in  the  section  on  ventilation  in  the 
chapter  on  general  design  of  pulp  and  paper  mills. 

Pitch  Spots  on  Wire:  These  cause  small  holes  in  the  paper. 


PAPER  DEFECTS;  THEiR  CAUSE  AND  CURE  505 

The  pitch  fills  up  the  meshes  of  the  wire  and  no  stock  occupies 
this  space  and  consequently  no  paper  is  formed.  The  cause  of 
pitch  goes  right  back  to  the  nature  of  the  wood  used  for  pulp. 
Some  woods  naturally  produce  more  pitch  than  others.  It  also 
depends  on  cooking  conditions.  The  presence  of  gypsum  or 
calcium  sulphate  in  the  cooking  acid  will  tend  to  increase  pitch,  as 
the  small  granules  of  this  material  form  nuclei  around  which 
pitch  collects.  This  gypsum  or  calcium  sulphate  in  the  acid  is 
due  to  improper  burning  of  the  sulphur  to  a  large  extent.  This 
case  is  illustrative  of  the  manner  in  which  the  various  parts  of  a 
pulp  and  paper  mill  depend  on  each  other.  Troublesome  holes 
in  the  paper  may  in  this  case  be  traced  directly  back  to  ineffi¬ 
ciency  in  the  sulphur  burners.  This  subject  is  also  touched  in 
the  chapters  on  the  sulphite  mill  and  acid  plant. 

The  immediate  cure  for  this  evil  is  to  thoroughly  clean  the 
wire.  Sometimes  a  steam  jet  will  soften  the  pitch  -and  enable 
it  to  be  washed  out.  Great  care  should  be  taken  when  removing 
pitch  not  to  injure  the  wire.  However,  this  is  merely  a  tem¬ 
porary  remedy.  If  pitch  spots  occur  once  they  will  occur  again. 
The  real  cure  is  to  thoroughly  investigate  the  fundamental  cause 
and  attempt  to  cure  that. 

Lumps:  Lumps  or  “slugs”  are  caused  by  little  hard  accre¬ 
tions  of  stock  forming  on  the  deckle  strap  or  elsewhere  and  fall¬ 
ing  onto  the  surface  of  the  sheet.  Similar  lumps  are  sometimes 
caused  by  fibres  forming  into  knots  on  the  under  side  of  the 
screen  plates  and  when  they  become  heavy  enough  dropping  off 
into  the  stock.  This  has  been  discussed  in  describing  the  con¬ 
struction  and  operation  of  screens  in  the  chapter  on  the  machine 
room.  Almost  anywhere  that  stock  has  a  chance  to  churn 
around  for  any  length  of  time  not  too  violently  such  lumps  will 
form. 

These  lumps  will  be  pressed  out  forming  blotches  which  in¬ 
terrupt  the  continuous  strength  of  the  paper  and  afford  an  oppor¬ 
tunity  for  breaks,  especially  if  near  the  edge. 

A  hole  in  the  apron  is  another  cause  of  such  breaks.  The 
tendency  of  the  stock  to  run  down  through  the  hole  will  draw 
fibres  into  it  which  will  be  packed  hard  against  the  wire  into  a 
little  knot.  As  soon  as  this  is  dislodged  another  will  start  to 
form  and  this  hole  will  thus  provide  a  constant  source  of  these 
lumps,  and  the  source  may  not  be  discovered  until  the  holes 
wear  large  enough  to  be  readily  perceptible. 

The  cure  for  this  class  of  troubles  depends  on  the  particular 
source.  If  it  is  the  screens,  the  trouble  probably  is  that  the 
stock  is  standing  too  high  in  the  vat.  Jf  the  lumps  are  found 
to  come  from  the  deckle  strap,  the  showers  and  poppets  (or 
troughs  through  which  the  deckle  straps  pass)  should  be  ex¬ 
amined  to  see  that  they  are' exerting  their  proper  cleansing  func¬ 
tions.  If  a  hole  in  the  apron,  the  apron  must  be  mended  or  re¬ 
placed.  A  good  sharp,  clean  shower  back  of  the  breast  roll, 


5o6  modern  pulp  AND  PAPER  MAKING 

under  the  apron,  spraying  water  on  the  apron  and  the  wire  will 
help  dispose  of  all  such  lumps  if  any  ate  forming. 

Wet  Spots:  Any  bruise  or  depression  in  one  of  the  press 
rolls  will  cause  the  paper  which  that  spot  comes  in  contact  with 
to  be  somewhat  wetter  than  the  average.  This  wetness  will  not 
be  removed  by  passing  through  the  other  presses,  even  by  pass¬ 
ing  over  the  dryers  in  some  instances,  because  it  will  always  be 
a  little  wetter  than  the  remainder  of  the  sheet.  If  wet  enough 
when  it  reaches  the  calenders  such  a  wet  spot  will  give  rise  to  a 
blemish  looking  much  like  a  slime  spot,  all  the  fibres  being 
crushed  and  moulded  together  into  a  glazed  blotch  without 
strength  and  marring  the  look  of  the  sheet.  Obviously  the  cure 
is  to  repair  the  offending  roll. 

Sawdust  Spots:  Ground  wood  pulp,  unless  very  carefully 
screened,  will  contain  some  sawdust.  Moreover,  in  making  sul¬ 
phite  pulp,  sawdust  frequently  does  not  cook  in  the  digesters, 
remaining  hard  and  woody.  By  rights  there  should  be  no  saw¬ 
dust  in  the  chips,  if  they  are  properly  screened,  but  sometimes 
through  carelessness  or  the  use  of  poor  equipment  some  sawdust 
gets  into  the  digesters,  and  probably  with  the  best  practice  there 
is  always  a  little  which  has  adhered  to  the  chips  in  spite  of  all 
precautions. 

These  particles  of  sawdust  will  go  right  through  with  the 
stock  into  the  beaters  and  into  the  paper  machine.  There  they 
may  form  a  blemish  out  of  all  proportion  to  their  size,  these 
marks  sometimes  being  as  large  as  a  silver  quarter.  This  is 
because  the  sawdust  holds  the  sheet  up  off  the  dryers,  letting  it 
remain  wet  in  a  small  circular  area  surrounding  the  piece  of 
sawdust.  When  the  sheet  reaches  the  calenders  this  wet  spot 
will  be  crushed  in  the  manner  described  under  the  heading  wet 
spots  above.  However,  this  sort  of  blemish  can  usually  be  dis¬ 
tinguished  from  an  ordinary  wet  spot  as  the  sawdust  or  the  trace 
it  has  left  can  usually  be  recognized  in  the  center  of  the  blemish. 

The  cure  for  this  condition  is  more  careful  sawing,  screening 
and  chipping.  However,  if  the  screens  on  the  paper  machine  are 
in  good  condition  they  should  catch  such 'particles,  so  that  if  saw¬ 
dust  spots  are  appearing  it  would  be  a  good  idea  to  look  and  see 
if  the  screen  plates  have  not  been  bent  by  someone  stepping  on 
them  or  dropping  a  tool  on  them  or  pounding  them  too  hard  with 
a  slapper. 

_  Pin  Holes:  Sometimes  a  sheet  of  paper  will  display  .small 
glistening  particles  which  fall  out,  leaving  little  pin  holes  when 
the  sheet  is  crumpled.  The  glistening  material  is  gypsum  or 
calcium  sulphate  formed  in  the  cooking  acid  on  account  of  SO., 
being  present  in  the  sulphur  gas.  Therefore,  the  cure  for  this 
trouble  goes  right  back  to  the  sulphur  burners,  and  for  the  de¬ 
tails  of  this  the  reader  should  consult  the  chapter  on  the  acid 
plant.  Naturally  this  defect  can  only  occur  in  papers  containing 
sulphite  stock. 


PAPER  DEFECTS;  THEIR  CAUSE  AND  CURE  507 

Thin  Streaks  Due  to  Ridged  IFire:  If,  for  any  reason,  such 
as  a  lump  of  stock  adhering  to  a  carrying  roll  or  the  breast  roll, 
the  wire  acquires  a  ridge,  the  stock  will  not  form  on  this  ridge, 
or  at  least  will  not  form  as  thoroughly  as  on  other  portions  and 
this  will  yield  a  thin  strip  reaching  lengthwise  of  the  sheet. 
There  is  no  real  permanent  and  sure  cure  for  a  ridged  wire.  In 
the  hands  of  a  careful  operator  a  wire  will  hot  become  ridged. 

Thin  Streaks  Due  to  Seam  of  IFire:  Sometimes  the  seam  of 
the  wire  will  fill  up  and  make  a  thin  streak.  This  sort  of  thin 
streak  runs  across  the  sheet.  It  is  the  result  of  a  bungled  job 
at  seaming  and  there  is  really  no  cure  for  it.  It  is  a  case  where 
the  paper  maker  can  learn  from  experience. 

Blow  Marks:  Air  will  sometimes  get  under  the  paper  as  it 
passes  into  the  pinch  of  the  press  rolls.  This  air  will  raise  up 
the  sheet  in  a  sort  of  bubble,  which  will  be  ironed  out  as  the 
sheet  goes  through  the  press.  The  air  will  make  two  paths  or 
trails,  one  on  each  side  of  the  bubble,  just  as  will  happen  if  you 
run  a  roller  along  a  rubber  tube  full  of  air.  These  trails  will 
leave  marks  on  the  paper  which  are  easily  recognized  by  their  oc¬ 
curring  in  pairs. 

When  the  bubble  is  pressed  down  it  will  overlap  the  remain¬ 
der  of  the  sheet  at  each  side.  The  mark  will  thus  finally  appear 
as  two  thick,  irregular  blotches,  running  the  length  of  the  sheet, 
separated  by  a  thin  patch  between  them.  One  cure  for  this  is 
to  place  a  small  very  light  felt  covered  roll  on  the  paper  after  it 
has  been  carried  across  from  the  couchers  to  the  first  press. 
This  roll  will  ride  on  the  paper  and  insure  it  entering  the  pinch 
of  the  press  level  and  free  from  air.  This  trouble  cannot  well 
occur  on  machines  equipped  with  suction  press  rolls  as  the  air  is 
thoroughly  drawn  from  under  the  sheet  by  suction.  On  the 
usual  machine,  however,  there  is  no  place  for  the  air  to  escape 
to.  This  trouble  is  most  likely  to  occur  when  the  felt  has  just 
been  washed  and  is  so  wet  that  air  cannot  pass  through  it.  It  is 
not  a  constantly  occurring  trouble  and  one  may  make  a  lot  of 
paper  without  experiencing  this  difficulty,  but  we  mention  it  so  it 
will  be  recognized  when  it  does  take  place. 

The  above,  of  course,  are  not  all  the  possible  defects  that  can 
occur  in  making  paper.  On  such  a  complicated  machine  as  a 
Fourdrinier  paper  machine  new  sets  of  circumstances  are  always 
happening  which  will  lead  to  unexpected  results.  The  thing  to 
do  is  to  get  at  the  source  of  the  trouble  by  a  process  of  elimina¬ 
tion,  examining  and  dismissing  the  more  to  be  expected  sources 
of  trouble  first,  one  by  one,  before  the  more  unlikely  reasons  are 
looked  into.  This  is  just  as  in  finding  out  why  an  automobile 
refuses  to  go.  One  does  not  take  the  ignition  system  to  pieces 
until  one  has  ascertained  if  there  is  any  gasoline  in  the  tank. 
Defects  may  be  very  persistent  and  mysterious,  but  continued 
careful  investigation  will  reveal  the  cause  of  all  of  them  and 
when  the  cause  is  arrived  at  the  defect  can  be  remedied. 


.XIX.  Personnel. 


Now  that  the  mechanical  operations  and  the  chemical  and 
physical  changes  involved  in  the  manufacture  of  pulp  and  paper 
have  been  thoroughly  discussed  it  is  necessary  to  consider  an¬ 
other  vital  factor  in  paper  making.  There  is  nothing  more  essen¬ 
tial  in  the  conduct  of  a  successful  paper  industry  than  an  effi¬ 
cient  operating  force.  A  mill  may  have  been  designed  by  the 
most  experienced  and  ingenious  engineers,  it  may  be  equipped 
with  all  the  latest  and  most  efficient  machinery  regardless  of  ex¬ 
pense,  the  raw  materials  may  be  of  the  best  and  highly  trained 
chemists  may  be  at  hand  to  supervise  each  operation  in  accord¬ 
ance  with  the  best  scientific  practice,  and  yet  such  a  plant  may 
barely  struggle  along  on  account  of  neglect  of  the  human  factors 
entering  into  paper  production. 

Co-operation  in  the  Organization.  / 

The  personnel  of  a  pulp  and  paper  manufacturing  concern 
means  the  entire  assemblage  of  people  from  the  president  down 
to  the  most  insignificant  laborer  who  are  in  any  way  concerned 
with  the  necessary  activities  of  the  organization.  The  personnel 
of  all  pulp  and  paper  concerns  is  much  the  same.  First  there 
are  the  general  executives  whose  duty  it  is  to  supervise  financing, 
manufacturing  operations  and  future  development,  the  purchase 
of  raw  materials,  the  general  sales  policies,  etc.  The  vast  num¬ 
ber  of  those  employed  in  such  an  industry  never  come  in  direct 
contact  with  these  activities,  but  it  should  be  remembered  that  if 
these  large  affairs  are  not  attended  to  in  a  faithful  and  judicious 
manner  all  work  further  down  the  line  would  be  of  no  avail. 
Next  there  come  those  in  charge  of  various  special  departments, 
and  between  such  executives  there  must  be  actual  and  intelligent 
co-operation  if  maximum  efficiency  is  to  be  obtained  in  the  con¬ 
cern  as  a  whole.  Such  men  are  the  sales  manager,  the  adver¬ 
tising  manager,  the  general  purchasing  agent,  the  chief  chemist 
and  finally — most  important  of  all — the  superintendent  or  mill 
manager  or  whatever  it  may  be  decided  to  call  the  man  who  is 
actually  in  charge  of  the  manufacturing  plant. 

To  illustrate  the  need  of  co-operation  between  these  men,  if 
the  sales  manager  has  no  conception  of  the  difficulties  and  intri¬ 
cacies  of  manufacture,  it  is  obvious  that  he  cannot  market  the 
concern’s  product  in  a  very  intelligent  manner.  He  is  hardly  in 
a  position  to  answer  complaints,  to  accept  or  reject  important 
orders  which  require  immediate  decision,  or  to  direct  the  work 
of  his  subordinate  salesman. 


508 


PERSONNEL 


509 

Similarly,  the  advertising  manager  is  the  man  through  whom 
the  concern  speaks  to  the  public,  or  that  section  of  the  public 
where  its  customers  and  potential  customers  are  found.  It  is 
self-evident  that  such  a  man  cannot  talk  convincingly  about  some¬ 
thing  he  knows  nothing  about.  He  must  know  the  company’s 
product  from  the  wood  pile  to  the  finishing  room. 

If  necessary  co-operation  between  the  purchasing  department 
and  the  manufacturing  department  is  lacking  much  needed  sup¬ 
plies  and  equipment  will  not  be  on  hand  when  needed,  many  un¬ 
necessary  or  unwise  purchases  will  be  made  and  much  money 
and  time  will  be  wasted. 

The  necessity  for  the  closest  of  relations  between  the  chem¬ 
ical  laboratory  and  the  manufacturing  department  is  too  obvious 
to  even  comment  upon.  If  the  chemist  is  to  be  any  good  at  all 
to  the  concern  he  must  be  familiar  with  every  stage  of  the  proc¬ 
ess  of  manufacture  and'  also  must  be  well  informed  on  general 
trade  conditions,  the  market  in  which  the  company’s  product  is 
sold,  what  the  competition  is,  etc. 

Requisite  Qualifications  of  a  Superintendent. 

The  superintendent  must  display  a  nice  balance  of  abilities. 
The  principal  qualities  to  be  looked  for  in  the  ideal  superinten¬ 
dent  are : — 

( 1 )  Practical  experience. 

(2)  Scientific  and  technical  knowledge. 

(3)  Business  sense. 

(4)  Ability  to  handle  and  get  on  with  men. 

Practical  experience:  This  has  no  necessary  relation  to 
length  of  time  spent  in  the  industry.  There  are  many  men  who 
have  spent  a  lifetime  in  an  industry  and  who  know  little  more 
than  when  they  began.  It  is  the  result  of  learning  day  by  day 
and  keeping  one’s  mind  open  and  not  making  the  same  mistake 
twice.  However,  other  things  being  equal,  a  man’s  experience 
generally  will  increase  as  years  pass  and  there  are  many  tricks 
of  the  trade  which  only  time  can  teach. 

Scientific  and  technical  knowledge :  This  does  not  necessa¬ 
rily  imply  training  in  a  technical  school  or  the  scientific  depart¬ 
ment  of  a  university.  It  is  the  result  of  an  alert,  inquiring  mind. 
In  the  course  of  years  spent  in  an  industry  a  man  with  the  scien¬ 
tific  trend  of  mind  will  find  out  why  things  are  done.  He  will 
not  be  satisfied  with  the  answer  that  they  have  always  been  done 
that  way.  A  college  training  is  an  excellent  thing  for  the  man 
who  knows  how  to  use  it  after  it  is  obtained.  It  opens  the  way 
to  many  short  cuts  to  knowledge.  However,  it  is  no  guarantee 
of  technical  ability  and  many  of  the  most  scientific  men  in  the  in¬ 
dustry  started  without  it.  The  truly  scientific  technical  man  is 
never  done  learning.  He  is  always  ready  to  consider  new  develop¬ 
ments.  In  this  he  can  be  helped  by  the  technical  periodicals  of 
which  there  are  several  excellent  ones  in  the  pulp  and  paper 


510  MODERN  PULP  AND  PAPER  MAKING 

industry,  by  meetings  of  technical  associations,  etc.  The  danger¬ 
ous  stage  is  when  a  man  thinks  he  knows  enough  ^  about  the 
industry.  Just  then  someone  is  sure  to  get  ahead  of  him.  There 
is  always  more  to  learn  about  any  industry,  but  especially  about 
an  industry  involving  such  a  variety -of  sciences  as  does  paper 
manufacture. 

Business  sense:  Cases  where  men  who  are  scientific  geniuses, 
and  who  have  had  a  long  experience  in  practical  vmrk,  have  failed 
absolutely  in  running  the  business  end  of  an  industry  are  too 
numerous  to  mention.  An  ideal  superintendent  must  know 
something  about  ordinary  business  economics.  He  must  rplize 
that  the  final  crucial  test  of  any  manufacturing  operation  is  ’’Does 
it  pay  ?”  A  wonderful  product  is  of  little  practical  value  if  it 
costs  more  to  make  than  its  sales  department  can  possibly  get  for 
it.  No  one  expects  a  mill  superintendent  to  be  a  financier  or  a 
commercial  genius,  but  he  must  have  a  grasp  of  the  ordinary 
principles  of  business. 

Ability  to  handle  and  get  on  with  men:  _We_  will  have  so 
much  to  say  on  this  subject  later  that  we  will  dismiss  it  here 
with  the  comment  that  it  is  the  most  important  requirement  of 
all,  because  if  a  superintendent’s  men  cannot  or  will  not  work 
with  him  he  is  automatically  prevented  from  displaying  his  other 
abilities. 

Co-operation  Among  the  Employees 

One  of  the  most  common  causes  of  imperfect  efficiency  in 
pulp  and  paper  manufacturing  industries  is  lack  of  co-operation 
between  the  various  departments  of  the  concern.  The  niost  fre¬ 
quent  cause  for  this  lack  of  united  effort  is  a  too  intensified  riv¬ 
alry  between  the  different  departments.  Rivalry  is  an  impulse 
that  can  be  utilized  to  advantage  if  it  can  be  kept  under  control. 
However,  this  is  hard  to  do.  Many  superintendents  make  the 
mistake  of  over-encouraging  rivalry  in  order  to  increase  produc¬ 
tion  and  lower  costs.  In  the  end  it  does  neither.  The  rivalry 
grows  and  in  the  end  is  replaced  many  times  by  an  actual  hatred. 

Rivalry  between  departments  is  detrimental  to  the  success 
of  the  mill  in  many  ways.  In  attempting  to  cut  down  costs  be¬ 
low  those  of  a  rival  a  foreman  may  release  one  or  more  of  his 
men.  His  actual  output  of  work  may  continue  up  to  standard 
for  a  short  period,  but  only  on  account  of  extra  effort  forced 
from  the  remaining  men  who  soon  become  dissatisfied  either 
through  overwork  or  sympathy  with  their  former  fellow  work¬ 
men.  However,  they  realize  that  they  are  being  driven  to  enable 
the  boss  to  make  a  good  showing.  Dissatisfaction  leads  either 
to  strikes  or  to  indifferent  work. 

Foremen  often  refuse  to  help  each  other  by  lending  help  or 
tools  in  time  of  trouble.  The  rivalry  between  foremen  will  be¬ 
come  so  intense  that  one  will  delight  to  see  the  work  of  an¬ 
other  suffer  even  if  the  whole  plant  is  inconvenienced. 


PERSONNEL 


511 

Rather  than  encouraging  men  to  outdo  each  other  it  is  better 
to  teach  that  if  the  whole  plant  benefits,  each  man  in  it  benefits 
and  that  therefore  it  is  not  only  right,  but  good  policy,  to  refrain 
from  doing  anything  that  will  cut  down  general  productiveness. 

The  relationship  between  men  and  their  bosses  plays  a  large 
part  in  the  success  of  the  paper  mill.  Every  boss  must  have  the 
good  will  of  his  men.  This  is  true  not  only  of  department  fore¬ 
men,  but  also  of  the  plant  superintendent  as  well.  The  superin¬ 
tendent  is  the  most  important  single  individual  in  the  personnel 
of  the  paper  mill.  He  must  keep  the  mill  runing  as  a  paying 
proposition.  He  must  ever  be  on  the  watch  to  reduce  unneces¬ 
sary  expenses.  He  must  adjust  labor  troubles  and  settle  dis¬ 
putes  among  the  men.  He  represents  the  owners’  interest  in  the 
concern.  To  be  successful  in  all  this  he  must  have  the  hearty 
co-operation  of  all  the  men.  This  can  only  be  secured  in  one 
way.  This  is  by  and  through  the  sincere  personal  regard  of  his 
men. 

Personal  Relations  between  Superintendent  and  Men. 

No  superintendent  can  direct  the  operation  of  a  mill  with  any 
hope  of  success  if  he  is  disliked  by  his  men.  Men  will  work 
under  a  superintendent  whom  they  dislike,  if  they  have  to,  but 
they  will  not  give  him  all  of  which  they  are  capable.  They  are 
bound  to  relax  as  soon  as  they  are  out  of  this  direct  observation. 
Some  superintendents  seek  to  govern  the  men  through  fear. 
Through  fear  a  man  may  be  .made  to  work,  but  he  cannot  be  made 
to  work  efficiently.  The  very  dread  which  some  superintendents 
inspire  in  their  men  causes  the  men  to  become  nervous  and  in¬ 
capable  of  doing  good  work.  No  man  knows  where  the  repri¬ 
mand  or  sarcasm  is  going  to  strike  next  and  suspicion  and  irri¬ 
tability  soon  prevails  throughout  the  whole  plant. 

The  superintendent  should  never  misrepresent  things.  If  he 
makes  a  promise  he  should  do  everything  in  reason  to  make  good. 
If  he  cannot  make  good  he  should  frankly  tell  the  reason  why. 

Needless  to  say,  the  superintendent  who  wants  the  co-opera¬ 
tion  and  respect  of  his  men  will  have  to  be  sociable  and  agree¬ 
able.  This  can  be  done  in  such  a  manner  by  a  man  of  good 
judgment  as  not  to  lose  the  respect  that  he  also  must  retain.  It 
is  a  matter  requiring  some  tact  to  retain  proper  respect  and  yet 
not  to  be  cold  and  distant.  Men  should  always  be  spoken  to 
when  they  are  met  during  working  hours,  or  on  the  street,  or 
anywhere  else.  The  writer  considers  any  man  who  works  for 
him  and  is  honest  as  a  friend  and  to  be  treated  as  such  both  in 
and  out  of  the  mill.  Some  superintendents  have  more  capacity 
than  others  for  remembering  names  and  little  things  about  men, 
but  it  is  a  great  help  if  a  superintendent  can  remember  some¬ 
thing  about  each  man  so  it  will  be  evident  when  he  speaks  to  him 
that  he  knows  the  man  as  an  individual.  One  map  likes  to  be 
questioned  about  his  family  and  another  about  his  garden  or 


512  MODERN  PULP  AND  PAPER  MAKING 

some  other  hobby,  and  if  a  man’s  relatives  are  ill  he  likes  to  have 
them  inquired  about.  These  things  are  little,  but  they  have  a 
powerful  influence  on  the  general  atmosphere  of  a  plant.  How¬ 
ever,  unless  the  superintendent  can  maintain  such  relations  natu¬ 
rally  it  is  better  not  to  attempt  it  at  all.  Insincerity  is  very  ap¬ 
parent  to  workmen. 

A  superintendent  should  always  believe  what  is  told  him  by 
his  men  unless  he  is  absolutely  sure  a  man  has  prevaricated.  In 
other  words,  a  man  gets  the  benefit  of  the  doubt.  If  it  is  found 
that  a  man  cannot  be  treated  in  this  manner  he  may  be  considered 
a  hopeless  case  and  should  be  dropped  out  of  the  organization. 

In  this  day  and  age  men  will  not  stand  for  bullying.  The 
writer  recollects  having  worked  for  men  whom  he  constantly 
feared  and  could  not  trust.  He  never  felt  sure  when  he  went 
home  at  night  that  he  would  not  return  the  next  day  to  find  his 
place  filled  with  some  other  man.  It  is  impossible  to  do  good 
work  for  an  erratic  and  overbearing  man  of  this  type. 

It  is  also  bad  policy  ever  to  interfere  with  foremen.  There  is 
nothing  a  capable  man  so  much  resents  as  to  be  placed  in  charge 
of  an  operation  and  then  to  have  the  superintendent  or  manager 
issue  instructions  to  some  man  under  him.  If  the  superintendent 
notices  something  obviously  wrong  he  should  go  to  the  foreman, 
not  to  one  of  the  workmen.  This  secures  the  confidence  of  both 
the  foreman  and  the  workmen. 

The  method  used  by  some  managers  of  going  to  workmen 
to  get  posted  as  to  the  details  of  operations  is  very  disorganiz-  ’ 
ing.  The  men  feel  that  when  they  have  a  grievance  they  must 
go  far  up  the  line,  even  to  the  president  of  the  company.  They 
feel  that  they  are  getting  more  credit  and  it  ends  in  making  a 
mere  figure-head  of  the  foreman  or  superintendent. 

A  superintendent  should  discourage  the  carrying  of  tales  to 
him  by  workmen.  Men  should  be  given  to  understand  that  they 
must  settle  all  differences  calling  for  adjustment  with  their  imme¬ 
diate  superiors. 

It  is  bad  to  spy  over  men.  It  is  not  only  objectionable,  but 
futile.  No  system  of  spying  could  possibly  be  effective  unless 
it  involved  much  waste  of  time.  Mills  have  to  work  nights  as 
well  as  days  and  men  have  to  be  trusted  to  do  their  own  work 
properly. 

The  writer  has  known  superintendents  who  have  made  a  prac¬ 
tice  of  spying  on  their  workmen  at  night,  sometimes  as  late  as 
one  or  two  o’clock  in  the  morning.  When  anything  like  that 
becomes  known,  the  men  lose  all  confidence  in  their  superior 
and  feel  that  they  are  branded  as  dishonest.  It  is  well  for  a 
superintendent  not  to  go  near  the  mills  at  night  unless  in  case  a 
breakdown  or  some  other  exceptional  circumstance.  If  it  is 
necessary  to  go  into  the  mills  at  night  the  workmen  should  be 
let  know  of  it  in  some  manner  so  that  they  will  not  think  that  it 
is  spying. 


PERSONNEL 


513 


Bullying,  spying  and  overbearing  conduct  will  make  men 
secretive  and  much  harm  may  be  done  m  this  manner.  The 
writer  has  seen  cases  where  the  men  were  absolutely  afraid  to 
say  anything  about  any  accident  that  happened  during  the  night 
and  would  even  lie  about  them  because  they  knew  full  well  be¬ 
forehand  that  without  regard  for  the  circumstances  the  superin¬ 
tendent  would  accuse  them  of  sleeping  or  loafing  on  the  job.  In 
this  way  small  accidents  will  stand  unreported  and  may  grow 
into  serious  matters.  If  a  man  feels  that  he  is  sure  to  be  dis¬ 
charged  or  bullied  for  making  a  mistake  (perhaps  a  very  par¬ 
donable  and  natural  one)  he  will  invent  some  plausible  story 
about  it.  If,  however,  conditions  were  otherwise  and  he  was 
not  afraid  to  explain  about  the  mistake,  the  whole  matter  could 
be  discussed  and  there  would  be  small  chance  of  that  man  making 
the  same  mistake  again. 

Development  and  Training  of  a  Papermaker. 

Progress  is  not  quite  as  difficult  nowadays  as  it  was  when  the 
writer  began  his  trade.  At  that  time  the  paper  and  pulp  indus¬ 
tries  were  carefully  guarded  as  more  or  less  secret  processes 
which  was  a  great  handicap  to  anybody  undertaking  to  learn 
the  business.  For  instance,  the  position  of  machine  tender 
seemed  to  compare  very  favorably  with  the  position  of  locomo¬ 
tive  engineer.  I  mean  by  this  that  we  had  to  wait  until  some¬ 
body  died  or  grew  too  old  to  run  his  machine  before  we  ever 
•  had  an  opportunity  to  be  advanced  to  that  position. 

From  the  very  beginning,  or  the  bottom  round  of  the  ladder, 
up  to  the  point  of  being  a  machine  tender,  there  were  all  sorts 
of  obstacles  in  my  way.  I  was  obliged  to  start  in  the  machine 
room  and  do  all  of  the  dirty  work.  I  lugged  the  drinking  water, 
did  the  scrubbing,  passed  along  the  monkey  wrenches,  ran  er¬ 
rands,  hustled  broke,  and  was  not  allowed  to  become  too  much 
interested  in  the  skilled  part  of  the  work.  For  instance,  if  the 
paper  broke  on  the  machine  and  I  asked  the  machine  tender 
what  broke  it,  he  might  tell  me  that  the  break  came  from  the 
stuff  chest,  or  it  might  be  the  fault  of  the  pump  in  the  basement 
or  some  other  way  of  misleading  me  as  to  the  real  cause. 

Perhaps  this  would  be  a  good  place  right  here  to  say  that  a 
young  man  who  starts  in  to  learn  the  paper  business  has  not 
necessarily  got  to  start  in,  in  the  machine  room,  but  without  in¬ 
fluence  it  naturally  follows  that  a  young  man  must  take  a  posi¬ 
tion  wherever  he  can  get  it,  whether  he  begins  at  the  vmod  pile 
and  works  forward  or  at  the  finishing  room  and  works  back,  or 
again  in  the  machine  room  and  works  both  ways.  In  any  event 
he  must  cover  the  ground  thoroughly  in  order  to  be  proficient. 

At  this  time  also  there  were  no  unions  to  protect  a  man  from 
unfair  treatment  or  from  ugly  and  overbearing  superintendents. 
If  I  were  asked  to  work  even  48  hours  consecutively  without 
sleep,  I  did  not  dare  to  refuse  because  it  would  cost  me  my  job. 


514  MODERN  PULP  AND  PAPER  MAKING 

Today  this  condition  is  far  different.  It  is  even  against  the  law 
to  compel  a  man  or  even  to  urge  him  to  work  beyond  the  speci¬ 
fied  hours  fixed  by  the  legislature.  Men  nowadays  must  be 
treated  like  human  beings. 

I  worked  for  at  least  two  years  as  roustabout,  cutter  man, 
third  hand,  winderman  and  finally  back  tender  before  I  could  get 
an  opportunity  to  try  my  skill  at  operating  a  machine,  and  I 
would  not  have  had  a  chance  even  then,  had  it  not  been  for  the 
fact  that  the  machine  tender  wanted  to  go  away  on  a  vacation  and 
there  was  no  one  else  whom  he  would  trust  to  take  his  place 
while  he  was  gone,  except  myself.  This  merely  broke  the  ice 
for  me,  but  did  not  put  me  in  more  of  a  hopeful  position  for  get¬ 
ting  a  machine,  because  there  was  still  the  obstacle  of  waiting 
for  a  dead  man’s  shoes. 

There  is  another  phase  to  the  question  which  has  occurred  to 
me  repeatedly  since  I  have  been  in  charge  of  mills,  which  is  that 
owing  to  my  own  experience  I  have  been  able  to  decide  with 
some  degree  of  accuracy  as  to  whether  an  applicant  is  fitted  for 
the  position  which  he  seeks. 

Since  pulp  and  paper  manufacturing  plants  run  day  and  night, 
it  is  necessary  for  one  to  become  accustomed  to  night  work, 
which  is  very  unnatural.  It  does  not  require  a  stretch  of  imagi¬ 
nation  to  know  that  this  way  of  working  one  week  nights  and 
the  next  week  days,  will  upset  anybody’s  system.  One  cannot 
sleep  in  the  daytime,  nor  can  he  eat  rationally  at  night.  It 
causes  an  upsetting  of  one’s  whole  makeup,  brings  on  dyspepsia,  • 
insomnia,  and  various  unnatural  tired  and  wornout  feelings. 

I  have  frequently  had  application  from  college  men,  young, 
robust,  snappy  fellows,  who  wished  to  learn  the  pulp  and  paper 
business.  They  were  willing,  so  they  said,  to  start  in  at  the  bot¬ 
tom,  in  fact  they  wanted  to  cover  the  ground  thoroughly,  and 
would  take  their  turn  with  the  rest,  but  there  have  been  only  one 
or  two  out  of  the  many  men  whom  I  have  started  who  have  not 
fallen  by  the  wayside. 

First  of  all,  we  get  intelligent  young  men  right  after  their 
school  course,  unprepared  to^  stand  for  any  of  the  hard  knocks 
and  after  having  to  sacrifice  their  health  in  many  cases,  go  with¬ 
out  sleep,  and  perhaps  be  knocked  around,  and  having  their  in¬ 
telligence  insulted  (so  they  think)  by  the  rough  characters  they 
may  come  in  contact  with,  they  often  give  up.  I  mean  rough, 
not  in  the  sense  that  the  paper  makers  themselves  are  particularly 
rough,  hut  on  account  of  the  nature  of  the  work  which  has  to  be 
covered  during  the  man’s  advancement.  There  are  various  other 
reasons  why  a  young  man  will  drop  out  of  the  ranks  during  the 
journey  from  the  bottom  round  of  the  ladder  to  the  top. 

Very  frequently  a  young  married  man  makes  application. 
He  starts  in  and  finally  makes  the  excuse  that  his  wife  does  not 
^yant  him  to  work  nights.  Then  we  frequently  get  young  men 
who  have  absolutely  no  mechanical  ingenuity  or  ideas.  This  con- 


PERSONNEL 


515 


dition  is  really  hopeless.  It  is  a  well  defined  fact  that  it  is  use¬ 
less  to  try  to  make  a  farmer  out  of  a  mechanic  or  to  put  a  me¬ 
chanic  behind  a  plough. 

The  paper  and  pulp  industry  calls  for  a  so  many  branches  of 
work  other  than  the  mere  matter  of  making  paper  that  a  case  of 
this  kind  simply  wastes  the  time  of  the  employee  and  the  em¬ 
ployer  ;  putting  a  man  in  charge  of  expensive  machinery  who  has 
no  idea  of  the  care  of  such,  is  a  very  costly  experiment.  The 
man’s  judgment  never  is  anywhere  near  correct  and  he  makes 
very  costly  blunders  and  usually  does  not  succeed  after  wasting 
possibly  eight  or  ten  years  of  his  life. 

The  young  men  who  start  in  the  business  who  are  more  apt 
to  succeed  are  those  who  are  accustomed  to  rough  and  tumble 
work ;  have  the  determination  to  forge  ahead ;  are  not  too  sensi¬ 
tive  as  to  their  associates  and  are  usually  the  boys  who  have  had 
even  a  worse  and  a  harder  lot  before  they  started  in  with  the 
business,  together  with  a  natural  trend  for  mechanics.  You  can 
imagine  a  bright,  young  man,  with  a  college  education,  who  makes 
a  start  in  the  paper  business,  how  humiliated  and  insignificant  he 
must  feel  to  be  ordered  around,  since  he  has  been  accustomed  up 
to  that  time  to  polite  treatment. 

Then  there  is  the  intemperate  young  man.  I  had  rather  have 
a  good,  willing  fellow  that  is  reliable  and  temperate  than  to  have 
one  of  the  opposite  type  who  might  know  very  much  more  about 
the  business.  A  willingness  to  obey  orders  and  apply  oneself  to 
the  learning  of  the  business  is  a  good  asset. 

There  is  just  as  much  call  for  good,  reliable  conscientious 
and  steady  men  today  as  there  ever  was.  They  have  always 
been  at  a  premium  and  always  will  be. 

Then  there  is  the  disturber,  v/hom  we  sometimes  get  into  the 
organization.  Their  activities  in  an  organization  of  men  are  as 
harmful  as  a  rotten  apple  in  the  center  of  a  barrel  of  good  ones. 
They  will  do  more  towards  disorganizing  a  crew  of  men  in  one 
month  than  can  be  put  right  in  a  year,  and  then  it  cannot  be  made 
right  except  when  the  cause  is  removed. 

It  is  sometimes  very  hard  to  single  out  the  person  who  is 
spreading  unrest  and  discontent  in  your  organization.  These 
men  have  a  faculty  of  covering  their  tracks  to  a  great  extent  and 
have  caused  a  great  many  bad  disturbances. 

Now  some  of  these  causes  for  disqualification  of  an  employee 
can  be  charged  directly  to  the  individual  himself,  while  others 
are  inborn  and  cannot  be  remedied. 

Finally  the  qualifications  a  man  should  have  who  desires  to 
make  paper  and  pulp  manufacturing  his  life  profession  are : 

First — Physical  health. 

Second — He  must  be  absolutely  honest  and  trustworthy. 

q'hird — Willingess  to  undergo  and  put  up  with  the  various 
ordeals  he  must  pass  through,  as  he  goes  up  the  line  towards  pro¬ 
motion. 


5i6  modern  pulp  AND  PAPER  MAKING 

Fourth — He  must  have  a  natural  trend  toward  the  business, 
and  be  naturally  mechanical. 

Sixth — He  must  be  a  man  who  has  a  respect  and  deep  interest 
for  the  success  of  his  employer. 

Seventh — He  must  be  co-operative. 

Eighth — He  must  be  able  to  stand  all  of  the  disappointments 
and  obstacles  which  he  is  bound  to  encounter  and  be  willing  to 
help  and  assist  in  any  way  that  he  can  to  further  the  interest  of 
the  company  for  which  he  works. 

Ninth — He  must  have  stick-to-it-ive-ness  and  the  great  desire 
to  learn  the  business. 

I  call  to  mind  an  instance  which  happened  in  my  own  experi¬ 
ence  where  I  was  eligible  to  the  next  position  as  machine  tender, 
as  I  was  the  oldest  employee  in  that  department.  I  had  been 
promised  by  the  superintendent  that  I  could  be  assured  of  the 
next  place.  After  some  time  a  vacancy  occurred  on  one  of  the 
rnachines.  I  was  perfectly  sure  that  I  would  be  given  this  posi¬ 
tion,  but  to  my  chagrin  and  disappointment  the  superintendent 
put  his  pwn  son  over  my  head,  into  the  position  that  I  thought 
rightfully  belonged  to  me,  as  I  had  the  superintendent’s  word  of 
honor  that  I  would  get  this  position.  I,  of  course,  immediately 
quit,  and  by  doing  so,  I  lost  ground.  This  display  of  temper 
and  haste,  without  taking  second  thought,  cost  me  a  least  one 
whole  year  of  experience.  This  was  one  of  the  number  of  dis¬ 
appointments  which  a  young  man  must  put  up  with,  as  I  saw 
later.  If  I  had  stayed  I  would  not  have  lost  my  year’s  experi¬ 
ence  and  would  have  been  installed  as  machine  tender  before  the 
year  was  out.  I  speak  of  this  fact  because  I  run  across  these 
conditions  every  day. 

There  is  always  an  easy  way  to  smooth  out  misunderstand¬ 
ings  and  difficulties,  and  there  is  a  hard  and  rough  way.  I  am 
satisfied  that  one  cannot  unravel  and  smooth  out  a  misunder 
standing  with  men  by  bullying  or  insulting  methods. 

After  organization  is  formed  and  things  are  running  smoothly 
there  may  occur  a  vacancy.  It  may  be  the  foreman  for  the  yard 
operations ;  it  may  be  foreman  for  the  sawmill  department,  or 
some  place  where  a  man  must  have  charge  of  a  number  of  men. 
It  will  readily  be  seen  that  it  is  a  difficult  job  which  requires  a 
great  deal  of  careful  study  and  observation  to  go  into  a  crew  of 
workmen  and  select  a  foreman  to  take  a  position  as  just  de¬ 
scribed.  A  man  may  be  perfectly  competent  to  handle  the  job ; 
he  say  that  he  can  get  along  with  men ;  I  may  give  him  a 
position.  The  first  thing  I  know  some  of  his  help  come  into  the 
office  with  a  story  concerning  his  unjust  treatment. 

Some  men,  as  soon  as  they  are  advanced  a  few  steps,  get  .so 
overbearing  and  feel  that  they  are  so  much  better  than  the  men 
who  work  under  them,  that  it  is  quite  impossible  to  get  along 
peaceably;  they  become  arrogant,  and  overbearing  and  actually 
Spoil  their  prospects  for  any  position  of  trust  or  responsibility. 


PERSONNEL 


517 

Every  man  must  be  capable  of  his  job,  from  the  superinten¬ 
dent  to  the  broke  hustler.  The  superintendent  who  does  not 
know  how  to  handle  men  cannot  hope  for  success.  Besides  a 
thorough  knowledge  of  papermaking,  he  must  have  tact  and  fore¬ 
sight,  prudence  and  judgment.  This  is  true  of  the  foreman  also. 
Every  man  m  the  plant  must  have  a  thorough  knowledge  of  his 
job  and  he  must  be  physically  able  to  perform  its  duties.  If 
through  deficient  knowledge  or  physical  incapacity  a  man  de¬ 
pends  upon  others  to  help  him  perform  his  duties,  somebody’s 
work  is  bound  to  suffer  and  the  efficiency  of  the  mill  is  conse¬ 
quently  lowered.  No  man  should  be  called  upon  to  do  work 
of  which  he  is  incapable.  He  may  attempt  it,  he  may  almost 
succeed,  but  in  the  end  his  attempt  will  prove  a  decrease  in  the 
mill  efficiency. 

The  working  conditions  of  the  mill  must  be  favorable  in  order 
to  keep  the  personnel  up  to  standard.  The  truly  efficient  work¬ 
man  will  not  w’ork  in  a  mill  which  does  not  meet  the  condition  to 
which  he  has  been  accustomed  in  other  mills.  The  men  all  ap¬ 
preciate  the  little  consideration  which  their  employers  grant  them 
and  more  than  repay  the  small  cost  by  their  greater  efficiency 
of  the  work.  To  sum  up — each  man  in  the  paper  mill’s  person¬ 
nel  must  be  a  man  capable  of  his  job,  a  man  satisfied  with  his 
job,  a  man  loyal  to  his  job. 

Machine  Tender. 

The  machine  tender  is  responsible  for  the  operation  of  his 
machine  and  the  quality  of  the  paper  turned  out  by  it.  He  di¬ 
rects  the  work  of  the  back  tender,  third  hand  and  other  machine 
help,  although  the  more  detailed  supervision  of  these  men  is 
largely  in  charge  of  his  assistant,  the  back  tender. 

The  machine  tender  should  encourage  the  back  tender  to  ob¬ 
serve  his  manner  of  tending  the  machine  so  that  he — the  back 
tender — can  assume  those  duties  whenever  occasion  may  so  de¬ 
mand. 

The  machine  tender  is  responsible  for  starting  the  machine. 
His  immediate  concern  is  the  wire,  which  must  be  free  from 
slime  and  otherwise  ready  for  the  stock  to  flow  onto  it.  When 
the  machine  tender  is  perfectly  sure  that  the  wire  is  in  proper 
condition  he  begins  furnishing  up  the  vats,  screens,  pump  box, 
head  box,  save-alls,  etc.  It  is  his  function  to  decide  when  the 
stock  is  to  be  allowed  to  flow  onto  the  wire.  Erom  that  point  on 
the  back  tender  carries  the  paper  through  the  presses  and  over 
the  dryers.  While  this  is  being  done  the  machine  tender  inspects 
the  screens,  suction  boxes,  deckle  straps,  couch  roll  and  presses 
and  other^  parts  of  the  wet  end  and  takes  particular  notice 
whether  his  sheet  is  level  or  not,  which  can  be  especially  well 
noted  at  the  couch  roll,  and  makes  whatever  minor  adjustments 
may  be  necessary.  He  is  guided  in  this  by  the  weigh  sheet  which 
the  back  tender  tears  off,  weighs  and  brings  to  him  as  soon  as 


5i8  modern  pulp  AND  PAPER  MAKING 


the  dry  paper  is  going  through  the  calenders.  When  this  is  all 
done  and  everything  at  the  wet  end  is  running  smoothly  he 
should  take  a  general  look  over  the  dry  end  to  see  everything  is 

all  right. 


The  Back  Tender. 

The  back  tender  is  to  the  machine  tender  what  the  first  mate 
it  to  the  captain  of  a  vessel.  He  is  largely  responsible  for  the 
third  hand  and  other  help  around  the  machine.  By  devoting 
proper  time  and  attention  to  the  training  of  these  men  so  that  he 
can  rely  on  them  to  accomplish  their  work  in  a  quiet,  emcient 
manner  without  constant  directions  being  shouted  to  thern,  he 
can  leave  just  that  much  time  and  attention  free  for  acquiring 
the  further  knowledge  that  will  be  necessary  before  he  can  aspire 

to  the  position  of  machine  tender.  ,  •  • 

Similarly,  the  more  the  back  tender  can  devote  his  time  to 
routine  matters  and  the  supervision  of  the  other  help,  the  more 
time  the  machine  tender  can  give  to  inspecting  the^  maclime  and 
seeing  that  everything  is  in  the  best  working  condition,  determin¬ 
ing  the  cause  of  irregularities,  etc. 

The  chief  responsibility  devolves  on  the  back  tender  m  con¬ 
nection  with  breaks.  He  must  see  that  the  other  help  are  in 
their  proper  places  to  take  the  paper  after  he  personally  has 
passed  it  over  the  dryers,  etc.  During  wash-ups  the  back  tender 
should  be.  responsible  for  the  washing  of  the  felt,  being  assisted 
by  the  other  help,  and  the  machine  tender  being  free  to  look 
after  the  wire,  etc. 

When  starting  the  machine,  after  the  machine  tender  has  let 
the  stock  flow  onto  the  wire  the  back  tender  takes  the  sheet 
through  the  presses  and  over  the  dryers,  watching  to  see  that 
the  dryers  are  hot  enough  to  thoroughly  dry  the  sheet  before  it 
is  led  through  the  calender  stack.  The  third  hand  should  be  al¬ 
lowed  to  perform  this  work  from  time  to  time  under  the  direct 
supervision  of  the  back  tender,  who  should  take  care  to  see  that 
he  does  not  do  it  in  such  a  manner  that  his  hand  is  in  danger  of 
getting  caught  in  the  presses  or  dryers. 

If  the  dryers  are  working  properly,  the  back  tender  next  runs 
the  sheet  through  the  calender  stack  or  stacks  making  sure  that 
the  doctors  are  clean  so  as  to  prevent  calendar  spots,  and  seeing 
that  the  calender  is  properly  lubricated  so  that  there  is  no  slack¬ 
ing  back,  which  is  the  chief  cause  of  calender  cuts,  one  of  the 
most  objectionable  defects  in  paper. 

It  is  also  his  duty  to  see  that  the  paper  is  going  over 
from  the  calenders  to  the  reel  properly,  so  as  not  to  cause 
rolls  with  hard  and  soft  spots  on  the  reel.  We  have  already 
spoken  of  the  harm  this  does  in  the  chapter  on  the  finishing 
room. 

The  back  tender  should  see  that  the  floor  around  the  machine 
is  kept  in  an  orderly  manner  and  not  encumbered  with  broke. 


PERSONNEL 


519 

spears,  tools  or  rubbish  or  sloppy  with  stocks,  etc.  An  untidy 
floor  has  been  the  cause  of  many  an  accident. 

All  the  time  the  back  tender  should  be  learning  as  much  as 
possible  of  the  machine  tender’s  art  and  should  be  teaching  his 
own  to  the  third  hand.  In  this  way  he  is  preparing  himself  for 
advancement  and  training  a  man  to  take  his  own  place. 

The  back  tender  needs  to  be  a  man  of  resourcefulness  and 
able  to  think  quickly  in  an  emergency.  It  is  a  responsible  posi¬ 
tion,  but  one  full  of  opportunity  for  usefulness  and  for  future 
advancement. 

Third  Hand. 

Just  as^  the  back  tender  is  an  understudy  for  the  machine 
tender,  so  is  the  third  hand  an  understudy  for  the  back  tender, 
that  is,  he  should  be  if  he  is  ambitious  and  capable.  The  third 
hand  should  assist  the  back  tender  and  machine  tender  generally 
in  washing  up  and  in  renewing  felts,  wires  and  jackets.  By  so 
doing  he  will  learn  much  about  the  duties  of  the  men  immediately 
above  him. 

Making  splices  at  places  indicated  by  the  back  tender  is  a 
job  usually  relegated  to  the  third  hand,  and  it  is  a  very  important 
job  from  the  point  of  view  of  the  company’s  customers.  Crushes, 
calender  spots,  slime  spots,  etc.,  have  to  be  cut  out  and  a  neat 
splice  rnade  and  a  flag  inserted  in  the  roll  to  mark  the  location 
of  the  splice. 

The  third  hand’s  prospects  for  advancement  are  largely  de¬ 
pendent  on  his  avidity  for  work.  It  depends  on  the  man  him¬ 
self  whether  he  will  be  looking  for  opportunity  and  always  find¬ 
ing  some  way  of  being  useful  to  the  machine  tender  and  back 
tender,  or  whether  he  will  merely  do  what  is  absolutely  de¬ 
manded  of  him. 

Beaterman. 

The  position  of  beaterman  is  a  very  responsible  one  in  all 
mills,  and  one  where  a  great  deal  of  science  can  be  applied  if  the 
man  will  take  the  trouble  to  learn  from  observation.  He  should 
see  that  color,  size  and  alum  are  added  in  the  proper  order,  and 
at  sufficient  intervals  of  time  for  the  best  results  to  be  obtained, 
not  all  dumped  in  so  as  to  get  the  work  done  as  soon  as  possible. 
He  should  supervise  the  furnishing  of  lap  stock,  seeing  that  the 
beater  help  open  out  the  laps  properly  and  that  the  roll  does  not 
jump  as  the  laps  go  under.  He  is  responsible  for  the  condition 
of  the  roll  and  bed  plate,  the  keeping  of  the  beater  in  a  clean 
condition  (free  from  slime,  etc.)  and  the  entire  conduct  of  the 
operation.  Therefore  he  must  watch  the  appearance  and  feel 
of  the  stock  most  carefully,  regulating  the  roll  as  may  he  neces¬ 
sary  to  ^  secure  the  proper  result,  in  accordance  with  the 
general  instructions  of  the  superintendent,  and  his  own  judg¬ 
ment. 


520 


MODERN  PULP  AND  PAPER  MAKING 


Industrial  Bureau. 

The  past  few  years  has  brought  forth  the  need  of  maintaining 
within  the  pulp  and  paper  manufacturing  concern  a  department 
to  look  after  the  welfare  of  the  employees  and  to  serve  as  a 
medium  between  the  management  heads  and  the  employees  them¬ 
selves  The  problem,  however,  is  to  decide  just  how  far  to  go 
with  this  sort  of  work.  For  instance  it  is  reasonable  to  suppose 
that  a  company  employing  from  300  to  500  or  possibly 
men  on  the  payroll  can  not  afford  to  go  into  this  as  deeply  as  mills 
employing  from  20,000  to  40,000  and  incidentally  using  men 
speaking  several  languages.  The  name  applied  to  such  a  depart¬ 
ment  is  usually  termed  an  Industrial  or  Employment  Bureau. 

Regardless  of  how  large  the  personnel  of  the  Bureau  may  be 
the  following  two  main  divisions  of  activity  must  be  kept  in 

mind:  .  , 

I.  Getting  Workers ;  2.  Keeping  Workers. 

Getting  workers  necessarily  includes  the  following : 

I.  Getting  applicants  from  among  whom  to  select  the  workers. 

2.  Interviewing,  selecting,  examining  and  investigating  the  ap¬ 
plicants.  3.  Developing  labor  sources  from  within  the  plants. 

The  above,  of  course,  furnishes  but  a  very  much  simplified 
sketch  of  what  the  work  of  this  first  division  might  consist  of. 

Keeping  workers  might  include  some  of  the  following  ideas : 

I.  Accurate  enrollment  details;  2.  Intelligent  introduction  of 
workers  to  the  conditions  of  employment  to  their  supervisors: 

3.  Analyses  of  enrollment  of  details — age,  sex,  nationality,  in¬ 
telligence  and  experience ;  special  qualifications,  kind  of  work 
at  which  started;  supervision,  rate,  hours,  physical  conditions 
peculiar  to  the  individual ;  4.  Quiet  and  tactful  follow-up  of 
every  new  employee  to  determine  the  accuracy  of  placement, 
satisfaction  with  work,  attitude  of  co-workers ;  ^  5.  Familiarity 
with  progress  of  every  employee  through  watching  records  of 
attendance,  production,  wages,  transfers  and  suggestions  offered ; 
6.  Investigation  of  reports  of  dissatisfaction. 

In  order  to  carry  out  the  above  work  the  Chief  of  this  Indus¬ 
trial  Bureau,  that  he  may  carry  his  work  out  both  for  the  benefit 
of  the  organization  that  he  represents  and  the  employees  them¬ 
selves,  must  be  acquainted  with  the  following  details : 

I.  General  policies  and  supervising  personnel  of  the  indus¬ 
try  and  physical  working  conditions ;  2.  Conditions,  hours  and 
rates  of  neighboring  and  competing  industries;  3.  The  number 
and  kind  of  workers  needed  by  the  industry;  4.  Kind  of  work 
to  be  done;  5.  Conditions  of  work;  6.  Hours,  regularity  and  per¬ 
manency  of  work ;  7.  Kind,  amount  and  frequency  of  reward. 

In  the  present  stage  of  agitation  it  has  become  quite  neces¬ 
sary  to  employ  such  a  medium  for  watching  the  hiring  of  men. 
In  large  corporations  where  the  hiring  lies  entirely  in  the  hands 
of  numerous  foremen,  graft,  favoritism  and  autocratic  power 


PERSONNEL 


521 

often  result  and  men  discharged  in  one  department  for  being 
agitators  may  be  promptly  picked  up  by  another  foreman  who 
may  at  the  time  be  short  of  help.  Few  manufacturers  have  a 
real  live  Employment  Department.  The  old  system  of  letting 
the  foreman  hire  men  regardless  of  experience  and  qualifications 

APPLICATION  FOR  EMPLOYMENT  No..„ . . 

WITH 


Kote-AppUoUon  for  employment  must  be  made  out  aod  tigaed  pcraoii>Uy  by  appUcAnt  In  ink.  Bicb  question  must  be  answered  in  full. 


in  fall  (ao  ioitiala) .... 

*  Street  and  i 

Nnmber  { . 

Position  deaired.,..; . . 

Date  of  Birth . 

. . . 

What  laoguages  do  70a  speak?. 
Grammar  School  attended ..... 

Sigh  School  attended . 

Technical  School  attended . . 


City  or  i 

. Town  f . . 

....Wages  expected  per  | 

...Veer . Height 

State  or  1 

Country  f . 


Married  White  or 

•  or  single? . colored?. 


. . State . . 

Could  report  for  work - days  after  etigagement 

. Weight . Lbs. 

Have  you  been 

..  naturalized? . Dale . 


. . -  Have  lived  InUnited  SUles . 

No.  of  years . .  . Year  of  graduation . . 

.No.  of  years . Year  of  graduation . 

No.  of  years . .  Year  of  graduation . Degree. 


Give  below  four  employers  to  whom  we  esn  refer.  (Read  note  at  bntloui  of  this  blauk.] 


Time  Employed 
(Give  Month  &  Year) 

Name  and  address  of  Employer 

Name  of 

Foreman 

Kind  of  Work  Doue 

Wages 

Received 

1 . 

Reason  for  Leaving 

From 

Nauie 

, 

To  present  date 

Address 

From 

Name 

$: . 

Per 

To 

Address 

Prom  ' 

Name 

1 . 

Per 

To 

Address 

From 

Name 

$ . 

Per 

To 

Address 

Were  yoo  ever  employed  by  this  Company? . If  so,  vrbere  and  when? . 

Give  names  of  your  relatives  in  this  Company 's  employ . 

State  condition  of  yonr  health . Have  yoo  any' cliroiiie  ailment? . 

Are  yon  raptured? . Have  yon  ever  bad  tnberculosis? . Fits.or  epilepsy? .  .  Rhenmatisni?. 

Bsplain  fnlly  yonr  defects  in  sight,  speech,  hesriiig  or  limb . 


Give  below: 

Full  Names  of  IFving  Relatives  and  their  Home  Addresses 

wife  or  BMbead 

ChildrcQ 

Father 

Mother 

CiaodpareDU 

Brother* * 

'Mot  ere 

Incase  of  my  illness,  etc.j  notify. 


I  certify  that  my  enswen  to  the  above  qncstions  are  true,  and  J  alao  agree  that  Mid  questions  and  answers  shall  fonii  the  basis  of  my  employmeul. 
DaCe....__ . Telephone  No................ Sign  here  .  . . 


Fig.  216. 

is,  and  always  will  be,  a  big  expense  as  well  as  the  least  efficient 
way  of  securing  productive  labor.  The  management  that  per¬ 
mits  the  old  system  to  continue  either  through  ignorance  or  fear 
gives  no  attention  to  working  conditions  of  the  employees,  the 
very  backbone  of  the  industry,  and  the  employees  continue  to 
growl  and  agitate  trouble  at  the  smallest  disturbance.  Before 
installing  a  system  of  this  nature  the  writer  encountered  these 


522  MODERN  PULP  AND  PAPER  MAKING 

difficulties  daily.  Oftentimes  men  fired  in  one  department  for 
being  radical  agitators  have  in  a  short  time  returned  to  be  hired 
by  another  foreman,  unknowingly,  of  course,  as  he  had  no  ade¬ 
quate  means  for  investigating  the  past  of  this  particular  work¬ 
man.  Frequently  problems  dealing  with  the  welfare  and  better¬ 
ment  work  and  industrial  education  are  handled  by  the  same 
bureau. 

As  previously  stated  it  is  often  a  hard  question  to  decide  just 
what  the  powers  of  this  department  are  to  be — whether  the  em¬ 
ployment  manager  will  have  the  sole  right  to  select,  hire  or  fire 
workers:  whether  the  foremen  can  have  the  right  to  decline  to 
accept  workers  selected  by  the  employment  department :  whether 
the  rights  of  transfer  should  lie  in  the  hands  of  the  foremen  or 
the  employment  bureau. 

The  powers  of  such  a  department  are,  therefore,  largely  de¬ 
pendent  upon  the  nature  of  the  plant — in  specialized  work  with 
a  tightly  woven  working  organization  these  powers  might  lie  en¬ 
tirely  in  the  hands  of  the  Industrial  Bureau  with  advantage  to 
all  parties  concerned.  In  organizations,  however,  where  opera¬ 
tions  are  widely  diffused  and  varied,  as  is  the  case  in  most  pulp 
and  paper  mills,  it  is  best  to  adopt  an  intermediate  plan.  One 
organization  employing  1,500  men  has  an  Industrial  Bureau  con¬ 
sisting  of  a  Chief  and  two  alert  assistants.  The  forms  adopted 
and  the  powers  of  this  department  will  be  lightly  touched  upon. 

Figure  216 — Shows  a  usual  form  of  employment  blank.  All 
men  seeking  positions,  no  matter  to  whom  they  apply,  are  di¬ 
rected  to  the  Industrial  Bureau  where  they  are  interviewed  by 
the  Chief  of  the  Bureau.  The  applicants  are  then  requested  to 
fill  out  this  application  form  which  is  by  no  means  elaborate  and 
cumbersome  and  contains  all  the  data  essential  for  the  purpose. 
In  conjunction  with  this  form  is  used  a  follow-up  slip  on  each 
applicant  to  verify  the  statements  made  by  the  applicant  by 
writing  to  his  former  employers.  This  form  is  illustrated  by 
Figure  217. 

Each  morning  all  Superintendents  demanding  help,  call  the 
Industrial  Bureau  stating  the  type  of  man  wanted  and  nature  of 
jobs.  The  Chief  of  the  Bureau  then  looks  over  his  files  con¬ 
taining  the  waiting  lists  and  selects  the  men  suitable  for  the  jobs 
in  question.  This  man  then  reports  to  the  Bureau  and  is  given 
a  slip  illustrated  in  Figure  218.  Also,  if  the  Mill  Superintendent 
has  the  right  to  pick  out  a  man,  he  is  furnished  with  the 
form  shown  by  Figure  219.  The  man  with  this  form  must  report 
to  the  Industrial  Bureau,  where  he  will  properly  enroll  and  then 
report  to  his  Superintendent. 

The  man  then  reports  to  the  Superintendent  who  generally 
accepts  him.  If  he  has  any  reasons  for  not  accepting  the  man 
he  has  the  right  to  reject  him  but  must  first  state  his  reasons  for 
so  doing. 

We  now  have  the  man  installed  on  the  payroll.  It  is  the 


PERSONNEL 


523 


SMITH  &  JONES  PAPER  CO. 


•  ••••••.'•••a, 

(Place  &  Date) 


Dear  Sir: 

. of . 

applicant  for  a  position  with  us  as  . 

has  given  your  name  as  a  reference,  and  claims  to  have  been  em¬ 
ployed  by  you 

As  . PROM . TO . 

rate . CHECK  NO . 

. DEPT.  FOREMAN . . 

USING  REVERSE  SIDE,  kindly  advise  if  information  given  above 
IS  correct  and  whether  you  can  recommend  the  applicant  as  to  ability 
character  and  disposition.  Any  further  information  will  be  appreci¬ 
ated  and  treated  as  confidential.  ^ 

Very  truly  yours, 


authorize  you  to  furnish  the  information  requetsed 


Signature  of  Applicant 

Witness 


Fig.  217. 


duty  of  the  Chief  of  the  Industrial  Bureau  to  see  that  the  man 
is  content  with  his  job.  Special  provisions  are  made  to  educate 
the  foreigners  in  elementary  English.  The  application  of  ef- 

SUt*ERINTENDENT’S  NOTICE 
OF  REGISTRATION 


- - - - - 

Mr - - - Sup’t - Mill 

Mr - - - No _ _ 

has  registered  with  the  Indastrial  Bureau. 


Signed. 


Indu.strial  Bureau 


Fig.  218. 


ficiency  on  record  system  has  a  gratifying  effect  on  the  workers 
when  properly  applied.  It  minimizes  the  opportunities  for  dis¬ 
play  of  favoritism,  a  practice  that  is  often  abused  by  foremen 
m  positions  where  they  can  recommend  wage  increases.  It 
places  all  the  employees  on  an  equal  basis,  as  far  as  opportuni- 


524  MODERN  PULP  AND  PAPER  MAKING 

ties  for  increase  are  concerned,  and  it  puts  the  wage  increase 
problem  squarely  up  to  the  workers.  By  this  means  and  others 
for  keeping  in  close  touch  with  the  workmen,  the  highest  type  of 
efficiency  can  he  obtained;  for  it  is  only  when  working  under 
such  favorable  conditions  that  the  ordinary  worker  can  put  heart 

SUPERINTENDENT’S  ENGAGEMENT  CARD 


To  Payma-ster 
Name _ 


Card 

_ No.  . 


Local  Address - - - - - - ^ - — - — - - 

Date  Engaged -  - - - As - - 

For  Dep*t -  .—I - - 

Week 

Rate _ _ ^er  Hour - — - - - 

Old  No— _ .Signature  of  Employee - - - — - 

Reported  for  Week 

Snp’t _ M - 192 

Approved  by  General  Superintendent- - - - - - - 

Fig.  219. 

and  soul  into  his  work.  The  neglected  worker  usually  becomes 
indifferent,  drifts  or  stays  in  a  rut.  Welfare  work  with  the  in¬ 
tention  of  increasing  the  home  life  of  the  worker  will  often 
bring  an  improved  state  of  affairs.  One  of  the  most  practical 
ways  to  supplant  an  employee’s  indifference  with  interest  and 
enthusiasm  is  to  sell  him  as  many  shares  in  the  stock  of  the 


Reason 

Approved 


DEPARTMENT  TRANSFER 

To  Paymaster;  -  . *9* 

Name . - . - . . . - . . .  . . . 

Local  Place  of 

Address . . Birth .  . Age  .  .. 

Was  transferred  this  day  from-.- . .  .  .  .Department 

jQ  .......  ...  .  Department  to  be  Employed 

’as . . . at  rate  of .  per . — - 


Present  Rate .  . . Present  Occnpation  .  . - 

Approved; 

General  Supeiintendent 

Industrial  Bureau 

ReiK>rlcd  for  work  this  day  at . M. 

New  No . 

Fig.  220. 

Foreman 

company  as  he  cares  to  buy.  There  are  various  ways  of  selling 
the  stock,  such  as  the  installment  plan,  or  by  organizing  saving 
funds  which  will  be  used  to  buy  stock  as  soon  as  they  have 
reached  a  high  enough  mark. 

By  following  out  such  methods  the  man  takes  an  interest  and 
works  for  the  benefit  of  the  comj)any,  and  under  most  conditions 
will  soon  be  ready  for  a  transfer  or  promotion.  In  such  an 


PERSONNEL 


5^5 

event  the  mill  superintendent  (in  conjunction  with  the  Industrial 
Bureau)  arranges  a  transfer  for  this  man  to  a  better  job  in 
which  case  the  form  represented  by  Figure  220  is  made  out  and 
hied,  copies  going  to  both  the  paymaster  and  the  Industrial  Bu- 
reau.  If  it  is  purely  a  matter  of  rerating,  a  card  such  as  Figure 
221  IS  filled  in  the  two  departments. 

INDUSTRIAL  BUREAU 


l>iame . 

ReRated _ 

New  Rate.. 

Old  Rate _ 

Explanation 


. 192.J..* _ _ 

Per  Hour . 

Per  Hour . 


Approved 


Mill,  Fattory — Department. 


. Superintendent 

General  Superintendent 


Fig.  221. 

If  under  these  conditions  of  good  protection  by  the  Industrial 
Bureau,  a  man  fails  to  qualify  for  his  position,  shows  a  tendency 
to  be  an  agitator,  then  he  is  discharged.  He  is  given  Form  222, 
properly  filled  out,  and  submits  same  to  the  paymaster,  who  then 

REMOVAL  FROM  PAYROLL 
to  PAYMASTER:  . 


Please  Pay . . . ,  No. 

Occupation-. . .  . . 


(To  be  filled  o«t  by  Paymnstcr) 

Has  all  Co.  property  been 

Week  ending . 

surrended? . ,* . . 

Paid  on  Acc’t .  . 

ForeniRu  must  fill  out  Green 
•  copy  of  (bis  blank  and  seud  same 
promptly  to  Industrial  Service 

Net  Am’t  Due. . 

Checked  by^ . . . . . . 

Approved:.  Signed 


Fig.  222.  . 

pays  the  man  in  full.  At  the  same  time  Figure  223,  properly  filled 
out,  is  filed  by  the  Industrial  Bureau  for  further  reference  on 
the  adaptability  of  the  worker.  This  form,  as  indicated,  is  of  a 
confidential  nature. 

In  the  event  of  a  man  wishing  to  leave  for  good  reasons — not 
dissatisfaction — the  above  fornib  are  also  made  out  as  in  any 
other  instance. 

In  order  that  the  Industrial  Bureau  may  be  able  to  obtain 


526  MODERN  PULP  AND  PAPER  MAKING 

further  statistics  for  compiling  charts  Form  224  is  made  out  daily 
by  the  clerks  of  each  respective  mill. 

At  the  end  of  each  week  the  Industrial  Bureau  hands  to  the 
management  Form  225  containing  a  generalized  summary  of  the 
data  obtained  by  them  during  the  week.  This  form  enables 
one  to  trace  the  labor  conditions  throughout  the  plant,  and  any 


REMOVAI, 

Te  Industrial  Service  Devartnient: 

RECORD— [Confidential] 

^..193 

. . No...  — 

In  full  to  and 

(Cron  out  words  not  used) 

N  ational  ity - - - - - . . . -Age 


Reason  [In  full). 


[l)  Do  you  expect  to  reinstate? . . . [2]  Ability . . 

[3]  Character? . . - . —  W  Deportment? . . 

[5]  Would  you  re-employ  in  your  Dep't? . - .  [6]  Do  you  think  it  advisable  to 

re-employ  elsewhere? . . . — I?!  Industrious? . - . 

1 8]  Satisfied  with  shop  conditions  and  phy? . - . : . . . 

Approved:  Signed 


.Snp’f 


Fig.  223. 


ABSENTEE  REPORT 

Mr.  ^  _ _  Dep’t _  -  —  Date  . -  102 


■  Plesse  report  the  following  Absences  end  return  to  the  Industrial  Bureau  at  once 


Employee 

Mumber 

NAME 

REMARKS 

Excused 

Not  Excused 

Absence 

SalisFactoay 

Absence  Not 
Satisfactory 

Fig.  224. 

radical  changes  can  be  immediately  spotted  and  taken  care  of. 
From  this  data  the  Industrial  Bureau  graphically  shows  the 
Labor  Maintenance  and  Turnover  figures  for  various  periods. 

All  of  these  various  forms  are  kept  in  a  neatly  arranged 
folder  so  that  all  statistics  relative  to  one  man  are  always  avail¬ 
able  and  easily  found  when  properly  filed.  The  face  of  this 
folder  is  represented  by  Form  226. 


iNDusTRtAu  Bureau 


—Week  Endins- 


11  Feaimore  || 

Sulphite 

i 

&£ 

0 

B 

5 

w 

u. 

£ 

£ 

e 

«> 

< 

a 

£ 

e 

JU 

< 

■5^ 

e 

X 

1 

£ 

Stock  HandlerJi 

0 

u 

.cS 

m 

to 

Cartage  Bam  11 

s 

9 

0 

X 

» 

0 

0. 

oi 

« 

ee 

No.  S  Paper  jj 

a 

S 

a. 

0 

z 

41 

g 

(/> 

G.  Expense 

TOTAL 

l-“Avertje  No.  on  Roll 

2^TottI  Exits 

3 — TotsI  Entrsoces 

4 — Transfers  ’ 

S — Change  Rate  (Increase) 

^—Change  Rate  (Decrease) 

a 

7— -Applications 

8— Absentees  Investigated 

BT-Absentees  Without 

Notice 

lO-Liid  Off,  No  Work 

* 

11— Released 

12— Accidents 

13— Hours  Lost, 

Account  Accidents 

Noies! 


Indutirlat  Bureau 

Fig.  225. 

Employment  Bureau 


Ntmel 


- 

Began 

Clock 

No- 

Rate 

Dept. 

Tork 

Date 

Reason 

Trancfer'd 

Rate 

Changed 

Released 

. 

Fig.  226. 


527 


528  MODERN  PULP  AND  PAPER  MAKING 


Labor  Turnover. 

Labor  Turnover  is  the  result  of  many  causes,  dissatisfaction 
of  the  employee,  inefficiency  of  the  employee,  activities  of  agita¬ 
tors,  etc. 

This  Turnover  measured  in  dollars  is  generally  estimated 
from  $25  to  $150  per  employee  measured  by  the  following: 

1.  Placing  of  employees  in  departments  where  they  are  not 
adapted  to  tlie  nature  of  the  work. 

2.  Decreased  production  while  learning. 

3.  Cost  of  time  involved  while  teaching  the  new  operator. 

4.  Breakage  and  spillage  of  material  and  machines  as  a  result 
of  inexperience  on  the  part  of  the  operator. 

In  studying  this  proportion  of  labor  turnover,  we  find  sev¬ 
eral  important  factors.  These  have  developed  much  discussion 
among  those  who  have  studied  this  problem.  The  students  of 
the  question  may  be  divided  into  four  principal  groups : 

1.  Those  who  use  terminations  as  a  basis  for  figuring  labor. 

2.  Those  who  use  replacements  as  a  basis. 

3.  Those  who  use  payroll  figures. 

4.  Those  who  use  attendance  figures. 

From  the  above  the  only  conclusion  apparent  is  that  no 
definite  formula  has  yet  been  established  by  any  standard  com¬ 
mittee  for  computing  this  labor  turnover.  Moreover  all  the 
various  applications  have  their  merits  and  demerits. 

Talbot  has  devised  a  method  which  he  terms  Labor  Main¬ 
tenance.  Briefly  stated  we  record : 

Annual  growth. 

Periodic  growth. 

Specific  growth. 

Annual  growth  requires  additions  to  the  working  force  to  be 
retained  indefinitely.  Periodic  growth  needs  added  workers  at 
the  beginning  of  the  busy  season  to  be  laid  off  later  at  its  close. 
Specific  growth  also  requires  temporary  help. 

The  accompanying  chart.  Figure  227,  shows  such  conditions  as 
related  above.  In  the  background  are  sketched  the  numbers  of 
persons  at  work  week  by  week.  At  the  base  above  the  zero 
line,  are  sketched  in  solid  lines  the  number  of  men  taken  on, 
and  below  the  zero  line,  also  in  solid  lines,  are  sketched  the 
number  of  men  let  out.  To  gain  a  fairly  accurate  conception 
of  change  of  personnel  throughout  other  divisions  of  the  same 
organization,  similar  charts  should  be  for  each.  Charts  of  this 
nature  made  in  a  continuous  sequence  prove  almost  invaluable 
in  tracing  the  growth  or  decline  of  each  main  department,  in 
that  they  present  the  annual  growth,  seasonal  fluctuations,  and 
also  demonstrate  clearly  the  unnecessary  changes  taking  place 
during  the  height  of  production. 

This  form  is  made  out  weekly  and  filed  in  the  Industrial 
Bureau  and  serves  as  a  guide  or  check  to  the  form  which  we 


Totai.  No. 
ON  PArROUL.  ■ 

ISO 

/ss 

ISO 

us 
uo 
/  zs 
120 
IIS 

II  o 

/  OS 
I  OO 
9S 
90 

es 

BO 

7S 

70 

es 

eo 

ss 

so 

ss 

so 

3S 

30 

zs 
Zo 
IS 
!  O 

s 
o 


k 

V 

I 


ISIOMBEIt  4 

ON  2. 

/ 

0 

/ 

Nvmbsa  2. 
IsrOur.  3 
4 


/Z. 


LABOR  MA/NTENANCr 

WEEKLY 

General  ELxpense . 


S  5  «  S 


n 


Fig.  227, 


529 


MODERN  PULP  AND  PAPER  MAKING 


530 

will  now  describe,  which  is  placed  monthly  on  the  desk  of  the 
chief  executive  of  the  company.  Unlike  the  chart  mentioned 
this  form,  Figure  228  is  a  summarized  account  for  all  depart¬ 
ments  for  a  period  of  one  month.  In  this  'form  several  main 
features  are  brought  out: 

1.  Average  number  on  payroll. 

2.  Fluctuation  factor. 

3.  Per  cent  Turnover. 


Fig.  228. 


Item  one,  the  average  number  of  men  on  the  payroll  is  self- 
explanatory. 

Item  two,  the  fluctuation  factor,  shows  the  rise  or  decrease 
in  the  personnel  of  each  department.  For  example:  referring 
to  Form  228,  using  the  first  notation  “total  of  all  mills,”  we  have 
the  following  statistics  obtained  from  the  Industrial  Bureau: 

Average  Number  on  Payroll,  1,234. 

Total  taken  in,  78. 

Total  let  out,  55. 

In  this  particular  instance  we  have  78  men  taken  on  and  55 
men  let  out,  showing  55  complete  cycles.  It  is  this  factor,  and 


PERSONNEL 


531 

the  average  number  on  the  payroll,  that  we  use  as  a  basis  for 
figuring  the  percentage  turnover.  The  difference  between  num¬ 
bers  taken  on  and  number  let  out  we  designate  as  the  “Fluctua¬ 
tion  Factor,  in  the  case  it  is  positive — 23  men.  These  facts  are 
then  plotted  on  Form  228— the  heavy  black  line  indicating  the 
Fluctuation  Factor,  and  the  dotted  line  the  percentage  Labor 
Turnover.  By  means  of  such  a  form  the  executive  at  a  glance 
can  trace  the  labor  conditions  throughout  the  plant.  In  the 
event  that  the  turnover  is  relatively  high,  he  looks  up  the  report 
form  shown  in  Figure  227,  in  order  to  find  out  just  what  trend 
affairs  have  taken. 

The  above  forms  are  open  to  criticism,  like  all  other  forms 
that  are  in  use,  but  for  this  particular  line  of  work  they  have 
shown  themselves  to  be  useful  and  valuable  to  the  executive. 

Graphic  Reports. 

The  present  managers  of  corporations,  mostly  men  who  have 
risen  through  the  ranks  and  have  become  thoroughly  familiar 
to  the  relationships  that  one  department  bears  to  another,  have 
an  enormous  task  that  daily  confronts  them.  Important  de¬ 
cisions  must  oftentimes  be  made  at  a  moment’s  notice,  without 
opportunity  or  time,  for  a  voluminous  amount  of  correspondence 
and  calculation.  As  a  result.  Graphic  Records,  practically  un¬ 
known  a  few  years  ago,  have  become  generally  adopted  as  a 
proper  medium  for  the  quick  presentation  of  facts  in  nearly  all 
large  industries.  There  are  many  forms  and  appliances  for  the 
presentation  of  these  facts,  almost  all  of  which  are  applicable 
to  any  industry,  according  to  what  the  management  may  desire. 

To  the  trained  mind,  the  analytical  mind,  these  graphic  charts, 
when  properly  and  honestly  compiled,  furnish  a  medium  whereby 
he  develops  himself  at  the  same  time  that  his  job  is  growing 
need  not  spend  or  waste  time  looking  over  a  group 
of  figures  but  he  has  presented  to  him  a  picture  of  what  he 
wishes  to  see.  It  may  be  only  a  line,  it  may  be  a  group  of  lines, 
or  it  may  be  a  series  of  images,  but  in  all  instances  there  is  some 
one  feature  made  a  pronounced  factor,  enabling  him  to  grasp 
the  trend  of  affairs  in  the  space  of  a  few  minutes  of  time.  This 
visual  picture  becomes  a  fixed  factor  in  the  mind  of  that  ex¬ 
ecutive,  whereas  the  group  of  figures  would  soon  fade  into 
oblivion. 

If  from  the  above  it  is  seen  that  charts  help  to  visualize  the 
trend  of  affairs  that  they  tend  to  fix  facts  in  the  mind 
of  the  individual,  and  moreover  do  not  necessitate  the  expendi¬ 
ture  of  a  large  amount' of  money,  then  it  certainly  seems  logical 
that  charts  are  worth  while.  Even  if  the  executive  is  not  of 
the  analytical  mind,  then  it  is  to  his  advantage  that  he  adopt  this 
comparatively  easy  method  for  the  presentation  of  facts.  These 
charts^  may  be  made  flexible,  covering  many  operations  over  an 
unlimited  period.  Direct  and  indirect  labor  costs  can  be  traced 


532  MODERN  PULP  AND  PAPER  MAKING 

with  production  and  estimated  sales ;  costs  of  running  various 
departments  from  year  to  year  showing  seasonal  fluctuations ; 
comparative  quality  of  various  articles;  departmental  facts;  sales, 
etc.  All  of  these  facts  regardless  of  the  nature  of  the  business 
can  be  made  in  a  presentable  form. 

This  work  should  be  in  charge  of  a  conscientious  and  reliable 
man  (not  necessarily  a  technical  man),  for  once  the  system  has 
been  put  in  operation  the  work  is  quite  elementary.  The  facts, 
however,  must  be  honestly  presented  or  otherwise  the  work  is 
detrimental  to  the  executive.  It  is  the  function  of  this  man 
to  collect  for  the  business  all  the  data  and  facts  which  would 
be  of  any  assistance  to  the  executive,  the  officers  and  depart¬ 
ment  heads.  A  concern  doing  a  business  of  $1,000,000  per  year 
or  over  should  have  a  large  room  for  the  doing  of  such  work. 


/#0 


iSO 


no 


no 


too 


It  should  be  called  the  Record  Room,  and  be  an  adjunct  to  the 
Manager,  giving  him  all  the  data  portraying  the  running  condi¬ 
tions  for  which  he  is  responsible.  Definite  rules  should  be  made 
that  originals  should  not  be  taken  from  the  record  room,  but 
duplicates  or  blue  prints  should  be  obtained.  Only  by  following 
that  rule  will  the  system  prove  its  worth.  Of  course,  it  is  need¬ 
less  to  say,  that  adequate  facilities  must  be  given  for  filing  of 
the  completed  charts.  This  room  should  be  accessible  to  all 
department  heads  and  those  immediately  connected  with  the  va¬ 
rious  operations,  in  order  that  they  may  keep  in  touch  with  af¬ 
fairs  and  thereby  realize  the  advantages  of  such  a  system. 

The  nature  of  the  data  that  can  be  compiled  in  this  chart 
form  is  of  course  dependent  upon  the  industry,  its  size,  and 
the  financial  backing  of  the  Manager  or  President.  In  opera¬ 
tions  covering  the  manufacture  of  paper  we  have  adopted  sev- 


Fig.  229. 


PERSONNEL 


533 

eral  forms,  some  of  which  illustrate  but  one  fact,  others  covering 
period  of  one  week,  others  monthly,  etc,  ^ 

First  of  all  let  us  consider  charts  illustrating  tests  on  qual- 


Fig.  230. 


P'ig.  231. 


ity  of  paper  between  various  grades  in  some  instances,  and  also 
variations  from  day  to  day  on  the  same  grade. 

Figure  229  illustrates  the  fluctuation  in  quality  of  a  standard 
grade  of  paper.  This  chart  is  made  out  on  a  bar  principle. 


534 


MODERN  PULP  AND  PAPER  MAKING 


Tear 


MlfLLCR. 


Fig.  232. 


AfuuLmhf  TesTS,. 

^  SACfr3» 

CrBS,  Mvi.LKNL  s.  •»  *•  • 


Fig.  233. 

and  the  various  heights  of  column  readily  visualize  to  the  ob¬ 
server  just  how  that  particular  grade  of  paper  has  been  run¬ 
ning  from  time  to  time. 

Figure  230  is  a  chart  illustrating  the  same  facts,  but  by  the  use 
of  a  single  line,  instead  of  a  series  of  bars.  This,  of  course,  con- 


PERSONNEL 


535 

sumes  less  time  in  the  making  but  it  is  generally  conceded  by 
those  who  make  use  of  such  charts  that  the  bar  principle  is 
better,  where  but  one  factor  is  being  indicated. 

Figure  231  involves  two  factors  illustrating  the  influence  of 
moisture  in  a  sheet  of  paper,  where  the  tearing  resistance  of  the 
paper  is  emphasized.  In  this  chart  we  have  two  lines,  one  for 
tear,  and  the  other  for  the  Mullen  test  plotted  by  means  of  two 
factors,  one  the  moisture  contained  in  the  sheet  of  paper,  and 
the  other,  the  values  of  the  two  tests,  Tear  and  Mullen, ’each 
taken  individually.  At  a  glance  an  operator  can  ascertain  the 
relative  importance  of  moisture  in  a  sheet  of  paper  by  noting 
,the  rise  of  the  tear  line,  with  increased  moisture  content  contained 
m  the  sheet. 

Figure  232  like  Figure  231  illustrates  two  varying  factors  but 
presented  in  the  form  of  bars.  The  choice  between  these  two 
different  forms  must  be  left  to  the  preference  of  executive. 

Figure  233  shows  the  comparative  rating  of  different  sizes  for 
three  different  manufacturers.  The  bar  principle  here  is  un¬ 
doubtedly  the  best  presentable  form,  for  here  we  have  each  dis¬ 
tinct  group  of  sizes  separated,  with  the  varying  heights  of  col¬ 
umns,  plainly  discernible  to  the  observer. 

Figure  234  presents  a  type  already  described  but  upon  a  dif¬ 
ferent  form  of  chart.  This  form  is  quite  valuable  and  has  found 
a  wide  application  which  will  be  described  later  when  costs  are 
taken  up.  On  this  form  of  chart  not  only  a  graphic  form  can 
be  presented  but  actual  figures  csn  be  neatly  typewritten  in 
thereby  indicating  all  the  data,  a  picture  and  figures  at  the 
same  time. 

Figure  235  is  an  interesting  chart  showing  the  increased  amount 
of  alum  at  one  mill  as  compared  with  another  on  a  monthly  basis 
covering  a  combination  of  years  and  months.  This  chart  is 
interesting  in  that  these  two  mills  make  practically  the  same 
grades^  of  paper.  A  superintendent  receiving  such  a  graphic 
analysis  will  readily  see  that  something  is  wrong  and  will  proceed 
to  correct  the  cause  of  the  discrepancy. 

Figure  236  involves  principles  already  mentioned  but  presents 
an  interesting  viewpoint  in  that  reasons  for  rejection  of  paper 
are  discernible,  and  amounts  of  rejection  are  shown. 

Figure  237  again  illustrates  another  point  that  we  constantly 
watch  the  variations  in  sulphur  consumption  between  two  sul¬ 
phite  mills. 

^  This  is  only  one  of  many  forms  that  illustrate  the  fluctua- 
tions  between  the  workings  of  sulphite  mills.  Free,  total  and 
combined  acids,  with  resulting  quality  of  finished  pulp;  steam 
pressure ;  temperature ;  and  all  the  various  stages  of  the  process, 
when  tabulated  in  such  a  form,  often  bring  a  quick  decision  to 
the  executive  who  would  frequently  be  lost  if  all  this  data 
were  presented  to  him  in  a  tabulated  form,  or  as  miscellaneous 
groups  of  figures. 


WEARING  QUALITY 

CANBY 

DURABLE  KRAFT. 


Jfcl 


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104 
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loz 

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92 

96 

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Fig.  234. 


536 


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a 


ijTNLfi 


E^»|-rr. 


HXL 


Fig.  235. 


537 


538  MODERN  PULP  AND  PAPER  MAKING 

Figure  238  is  a  chart  showing  mean  average  consumption  of 
coal  per  ton  of  product  for  period  of  six  months,  quickly  bring¬ 
ing  out  important  facts.  This  is  a  simple  form  of  chart  but 


i"i  n  I  n  I  i~J  n  1 1 1  iioi  . . . 

^MCkViN  CmPIRC  .  CASE  MELVIN  EMIJflRS 


Fig.  237, 

the  facts  are  there  nevertheless  and  will  serve  the  purpose  of  a 
more  intricate  form  that  would  take  more  time  to  make,  and 
more  time  to  analyze. 


PERSONNEL 


539 


ia  S£.  e£  ^  - 


J  2.  L3L 


Cls 


iru  fuj^ 


£.eL 


i 


cs. 


a*. 


£.2^2. 


Atnu. 


j  b2<fc 


CitAT^Z. 


£.  2/ 


iS  — — 


Il  JS. 


Fig.  23<S. 


We  have  covered  briefly  in  a  general  way  charts  that  can 
be  made  useful  to  the  executives  of  a  pulp  and  paper  mill,  cov- 
enng  general  mill  operations,  quality,  etc.  We  will  now  give 


CASE 

PAPCR 

MILL 

FINISHINS 

ffOOM 


4^9.00 
B.7S 
a. So 

а. 2s 
8.00 

7.75 
7.  SO 
7.  25 
7.00 

б.  75 

5.50 

6.25 
e.oo 

S.  7S 
5. so 
s.zs 

5.00 
•4.  7S 
A. SO 

4.25 
4.00 
3.  75 
3-50 

3.25 
3-00 

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2. 50 

2.25 
2.00 
I  .75 
I  .SO 
I  .2S 
I  OO 

•  75 
.  50 

.zs 

.00 


540 


PERSONNEL 

COM PAR/SON  SACdBAS/S  wn/:ur.^ 


541 


’T'. 


COMPAR/SON  OF  OUTSIDE  SHEET 

spirit  BfiLs  eXoan  ■■ 

*/C/¥g-S  ^  ^ 


Fig.  241. 

m  a  brief  form  a  digest  on  various  cost  charts,  data  of  which 
must  come  from  the  Accounting  Department  and  be  put  into 

‘entadon*  “‘«''P>'etations  Ld  pre- 


542 


MODERN  PULP  AND  PAPER  MAKING 

Figure  239  shows  cost  of  roll  finishing  in  one  Finishing  Room. 
This  chart,  by  means  of  three  lines,  shows  quite  plainly  the  cost 
of  these  various  operations  from  week  to  week.  This  chart  if  it 


« 

?  ?  ? 


Co M PAnisoisi  OF  AvEf^Age  Vauoe:  ■" 


JBao 


Fig.  242. 


Tear  O* 


Bao  Sizes 


Bag  Sizes. 


Fig.  243. 


is  to  cover  a  period  of  one  year  should  be  made  out  in  a  form 
with  52  divisions  in  order  to  properly  cover  the  52  weeks  of 
the  year.  Following  are  illustrations  of  various  forms  of  cost 


PERSONNEL 

543 

shee  s  these  forms  can  be  superimposed  (a  chart  for  lom  can 

-p-d1^  =~ 

We  have  but  slightly  touched  on  this  subiect  hnf-  lnr>rt«  f 

to  the®';“p“T  ^n^dLst*^  T”r“°r  |-P«'  ^rS 

valuable  information  can  be  obtained  inT^^h 

enabling  the  executive  to  mat'ra'pld-d^a^o':;*  Svf  t^’S 

AVERAGE  COMPARISON  OlV  TOTAL. 


Fig.  244. 


branches  of  the  industry.  Further,  by  means  of  a  Technical 
bureau  daily  checks  and  test  runs  can  be  made  plotted  in  a  pre- 
^ntable  form  and  put  in  the  mills  for  the  benefit  of  the  men. 
How  this  IS  done  is  described  in  the  chapter  on  testing.  These 
records  are  invaluable  when  presented  in  the  proper  form  (not 
as  a  means  of  criticism  but  as  a  mean  of  arousing  interest  be¬ 
tween  individuals  and  units)  so  that  the  men  will  regard  this  as 
p  aying  or  scoring  m  a  pme.  _  It  has  been  necessary  to  reproduce 
all  the  charts  m  this  book  in  simple  black  and  white,  but  in 
actual  work  we  use  different  colored  lines,  columns,  etc.,  although 
various  kinds  of  dotted  lines  will  do  just  as  well.  There  ^is 
nothing  about  these  charts  peculiar  to  the  paper  industry.  Chem- 

pnH  ill  V  :i  smelters,  machine  shops,  department  stores,  banks 
and  all  kinds  of  plants  and  offices  use  them  constantly. 


XX.  Useful  Data  and  Tables. 


TRADE  CUSTOMS 

General  Rules  and  Regulations  Governing  the  Sale  of  Book 
Papers. 

MINIMUM  BASIC  WEIGHTS  without  extra  charge. 

COATED  BOOK  two  sides. 

COATED  BOOK  one  side. . 

S  &  SC  BOOK . 

ENGLISH  FINISH  BOOK 

M.  F.  BOOK . 

EGGSHELL  BOOK . 


25  X  38— TO 
25  X  38—60 
25  x  38—50 
25  X  38—45 
,25  X  38— 45 
,25x38—45 


For  LIGHT  WEIGHT  COATED  PAPERS  add  5  cents  per 
hundred  pounds  for  each  pound  below  the  minimum  basis  men¬ 
tioned,  down  to  60  pound  for  Coated  two  sides  and  50  pound 
for  Coated  one  side.  Any  papers  lighter  than  these  weights  are 
subject  to  special  price. 

For  LIGHT  WEIGHT  UNCOATED  PAPERS  add  5  cents 
per  hundred  pounds  for  each  pound  light  down  to  40  pound  and 
10  cents  per  100  pounds  for  each  pound  light  from  40  pound  to 
30  pound  basis. 

EXTRA  CHARGE  for  colors — other  than  White  or  Natural. 

On  Special  sizes  and  weights,  5,000  pounds  minimum  amount 
without  extra  charge. 

On  COATED  PAPERS  a  variation  in  weight  not  exceeding  5 
per  cent  over  or  under,  shall  constitute  a  good  delivery,  and  such 
papers  shall  be  billed  as  ordered.  The  same  applies  to  UN¬ 
COATED  PAPERS  except  that  if  variation  is  in  excess  of  2^4 
per  cent  below  the  ordered  weight,  paper  is  to  be  billed  at  actual 
weight. 

On  SPECIAL  MAKING  ORDERS  variation  in  amounts 
shall  be  accepted  as  follows : — 


COATED:  1  —  2V$Tons . 

2H- 5  “  . 

5  —10  “  . 

Over— 10  “  . 

UNCOATED:  1—  2  Tons . 

2-5  “  . 

6—20  “  . 

20  “  and  Upward 


. 20%  Over 

. 15%  “ 

. 10%  “ 

.  5%  “ 

15%  Over  or  Under 
10%  “  “ 

5%  “  “  “ 

3%  “  “  “ 


SPECIAL  TRIMMING  OR  PACKING  is  subject  to  addi¬ 
tional  charge. 


USEFUL  DATA  AND  TABLES  545 

ALL  CLAIMS  for  damaged  papers  must  be  reported  immedi¬ 
ately  in  order  that  the  paper  may  be  inspected  before  it  is  cut 
or  printed. 


Trade  Customs  for  Coated  Cardboards. 

I— STANDARD  THICKNESSES. 


Coated  Blanks 

2  ply  .012 

3  “  .015 

4  “  .018 

5  “  .021 

6  “  .024 

8  “  .030 

10  “  .036 

12  "  .042 

14  “  .048 


Tough  Check 
2  ply  .012 

4  “  .018 

6  “  .024 

8  “  .030 


Thick  China 
.011 


Translucents 

2  ply  .008 

3  “  .010 

4  “  .012 

5  “  .015 


Railroads 
2  ply  .012 

4  “  .018 

6  “  .024 

8  “  .030 


2—  VARIATION  IN  THICKNESS. 

.008  to  .029 — .001  above  or  below  ordered  thicknesses. 

.030  to  .042 — -.002  above  or  below  ordered  thicknesses. 

.043  and  heavier  5%  above  or  below  ordered  thicknesses. 

3—  STANDARD  STOCK  SIZES. 

For  Railroads,  Tough  Check,  Thick  China  and  Blanks — 22 
X  28. 

For  Translucents — 22^2  x  28^^. 

4—  STANDARD  STOCK  COLORS. 

For  Railroads  and  Tough  Check. 

Blue,  Buff,  Coral,  Green,  Orange,  Red,  Salmon,  Yellow.  In 
addition  to  White  and  Black. 

For  Thick  China  Add:  Gray,  Pearl. 

For  Translucents  and  Tinted  Litho.  Blanks:  add 
Flesh,  Green,  India  Tint,  Pearl,  Primrose,  Rose.  In  addition 
to  White. 

5—  SPECIAL  SIZES  AND  THICKNESSES. 

(a)  Minimum  quantity  at  base  price  for  sizes  which  cut  with¬ 
out  waste  from  Standard  Stock  rolls  will  be  not  less  than  the 
equivalent  of  5>ooo  sheets  22  x  28.  Smaller  quantities  may  be 
made  at  a  price  commensurate  with  the  increased  cost. 

(b)  Minimum  quantity  at  base  price  for  odd  sizes  and  thick¬ 
nesses  which  will  not  cut  without  waste  from  Standard  Stock 
rolls  will  be  not  less  than  the  equivalent  of  10,000  sheets  22  x  28. 
Smaller  quantities  may  be  made  at  a  price  commensurate  with  the 
increased  cost. 

6—  MINIMUM  STOCK  ORDERS. 

Minimum  quantity  at  base  price  of  stock  items  will  be  not  less 
than  one  standard  case.  Add  not  less  than  10%  for  broken  cases. 


546  MODERN  PULP  AND  PAPER  MAKING 

7—  SPECIAL  COLORS. 

Minimum  quantity  at  base  price  for  odd  colors  will  be  not  less 
than  equivalent  of  25,000  sheets  22  x  28  single  coated  one  side. 
Smaller  quantities  may  be  made  at  a  price  commensurate  with 
the  increased  cost. 

8—  OVER-RUNS  AND  UNDER-RUNS. 

All  special  orders  subject  to  over-run  of  10%  ;  where  maxi¬ 
mum  quantity  is  specified,  an  under-run  of  10%  will  constitute  a 
good  delivery. 

9—  CLAIMS. 

All  claims  must  be  made  promptly  upon  receipt  and  exami¬ 
nation  of  goods.  No  claims  can  be  allowed  on  goods  which  have 
been  cut  or  printed. 

Trade  Customs  for  Wrapping  Paper. 

All  orders  for  wrapping  paper  are  accepted  for  wrapping  pur¬ 
poses  only,  unless  otherwise  specifically  stated. 

All  wrapping  paper  will  be  made  on  a  basis  of  24  x  36 — 480 
sheets  only. 

All  wrapping  paper  to  be  billed  actual  scale  weight,  including 
twine  and  wrappers  with  a  leeway  of  five  per  cent  (5%)  over 
or  under  ordered  weight.  Wood  or  iron  cores  billed  by  weight 
or  piece  and  returnable  if  agreed.  Paper  cores  to  be  weighed 
with  the  paper  and  not  returnable. 

No  paper  to  be  made  one  weight  and  stenciled  another. 

Tissues. 

STANDARD  BASIS :  White  Tissue,  20  x  30,  480  sheets,  7 
pounds  to  the  ream.  Manila  Tissue,  24  x  36,  480  sheets,  10 
pounds  to  the  ream. 

OVER-RUNS  AND  UNDER-RUNS:  On  orders  for  spe¬ 
cial  sizes  or  colors,  ten  per  cent  (10%)  above  or  below  the  quan¬ 
tity  ordered  to  be  considered  a  good  delivery  and  accepted  by 
purchaser. 

MISCELLANEOUS  CONDITIONS:  All  paper  heavier 
than  10  pounds  to  the  ream,  24  x  36,  480  sheets,  to  be  sold  by  the 
pound,  weight  to  include  wrappers  and  twine.  Any  size  or¬ 
dered,  not  exceeding  i]/^  inches  smaller  than  regular  sizes  to  he 
charged  for  as  regular  sizes.  Regular  sizes  are  24  x  36 ;  20  x  30 ; 
15  X  20;  30  X  40,  and  ii  x  15. 

The  limit  in  weight  for  Tissue  Paper  shall  be  17  pounds  to 
the  ream,  24  x  36,  480  sheets.  Paper  made  in  excess  of  this 
weight  shall  be  classified  as  light  weight  Manila. 

Bonds,  Ledgers,  Writings,  etc. 

I.  On  special  sizes,  not  less  than  10  per  cent  additional 
price  for  lots  of  less  than  one  ton.  The  following  sizes  may  be 
considered  as  regular : 


USEFUL  DATA  AND  TABLES 


547 


FLATS  AND  BONDS 

14x17 

26x34 

17x26 

17x28 

19x24 

18x23 

28  X  34 

24  X  38 

23x36 

16x21 

19x26 

21  x33 

21  x32 

26x38 

30x38 

16x26 

19x28 

20x28 

17x22 

28x38 

28x40 

22x34 

19x30 

28x42V4 

22x25J^ 

LEDGERS 

14x17 

21  x32 

18x46 

17x28 

16x42 

19x24 

28x34 

17x22 

19x48 

15x  19 

22x34 

24x38 

19x30 

18x23 

20  X  28 

16x21 

23x36 

28x40 

LOOSE-LEAF 

16M  x21J^ 

22  x38 

23  x2i]A 

n^Ax22% 

22^x22}^ 

23Mx28i4 

mAx2i\i 

221^x28^ 

241^x2414 

29Kx28H 

22J4x34 

2414  x28}^ 

211^x311^ 

223^x25^^ 

24Kx29 

22  x34 

22Mx35H 

24>^x  3634 
2414x38 

Any  of  the  above  sizes  not  regularly  stocked  by  the  mill  in 
the  grade  ordered  may  be  considered  special  sizes,  but  these  and 
any  other  sizes  may  be  considered  regular  if  stocked  by  the  mill 
or  buyer,  but  all  special  orders  for  sizes  other  than  those  men¬ 
tioned,  unless  regularly  stocked,  shall  be  billed  at  lo  per  cent 
additional  in  lots  less  than  one  ton. 

2.  On  special  colors,  or  colors  not  regularly  ihade  in  the 
grade  ordered,  less  than  ton  lots,  not  less  than  lo  per  cent  addi¬ 
tional  price.  One  ton  and  less  than  two  tons,  not  less  than  5  per 
cent  additional.  Two  tons  and  over  open. 

Under  rules  Nos.  i  and  2  the  quantities  mentioned  are  un¬ 
derstood  to  be  the  quantities  named  in  the  original  order  or  in¬ 
quiry  and  not  the  quantities  that  may  be  arrived  at  by  adding  the 
10  or  15  per  cent  over-run  provided  for  under  rule  No.  4.  For 
example,  an  order  for  say  1900  pounds  is  an  order  for  less  than 
one  ton  and  is  to  be  billed  and  accepted  at  the  10  per  cent  ad¬ 
vance,  although  when  made,  the  allowed  over-run  may  make  the 
shipment  aggregate  more  than  2000  pounds. 

Under  this  rule  (rule  No.  2)  mills  may  make  in  any  estab¬ 
lished  grade  for  a  customer  buying  said  grade  regularly,  with¬ 
out  additional  charge,  such  colors  as  may  be  decided  upon  as 
constituting  the  regular  colors  of  such  customer’s  line. 

3.  On  all  Writing  Papers;  namely.  Fines,  Flats,  Ledgers, 
Bonds,  Linens  and  Typewriter  papers,  there  shall  be  a  differen¬ 
tial  between  the  price  of  white  and  colors  in  said  grades  and 
lines. 


548  MODERN  PULP  AND  PAPER  MAKING 

4.  On  special  orders  of  one  ton  or  less,  over-  and  imder-runs 
not  greater  than  15  per  cent  to  be  taken  by  customer.  On  orders 
for  more  than  one  ton,  over-  and  under-runs  not  greater  than  10 
per  cent  to  be  taken  by  customer. 

5.  Orders  for  less  than  a  full  package,  not  less  than  25  per 
cent  additional.  A  full  package  shall  be  construed  as  that  num¬ 
ber  of  sheets  which  it  is  the  custom  of  the  mill  to  use  in  wrap¬ 
ping  and  selling  the  item  of  paper  in  question. 

This  does  not  apply  to  orders  for  one  or  more  full  packages 
and  a  fraction ;  for  example^  an  order  for  NA  packages. 

6.  No  paper  made  one  weight  and  stenciled  another. 

7.  The  average  actual  weight,  including  wrappers,  not  to  ex¬ 
ceed  2^  per  cent  above  or  below  the  nominal  weight.  Paper 
within  this  range  to  constitute  a  good  delivery  and  to  be  billed 
at  the  nominal  weight.  The  above  to  be  based  on  items  of  one 
size  and  weight  on  individual  invoices. 

8.  No  claims  allowed  after  paper  is  cut,  ruled,  or  printed. 

Experience  has  shown  that  exceptional  cases  occasionally 

arise  where  the  fault  is  clearly  with  the  mill  and  where  an  abso¬ 
lutely  literal  enforcement  of  rule  No.  8  would  work  injustice 
and  hardship  to  the  merchants.  It  is,  therefore,  understood 
that  mills  will  enforce  the  spirit  of  this  rule,  deciding  excep¬ 
tional  cases  upon  their  merits  and  according  to  the  rules  of 
equity. 

9.  No  paper  of  private  watermarks  or  brands  to  be  supplied 
for  sampling  purposes,  nor  allowance  made  on  account  of  water¬ 
marks  or  brands, 

10.  All  “make  and  hold”  orders  must  specify  an  ultimate 
date  for  shipment,  at  which  date  goods  are  to  be  billed  and  tbe 
invoices  taken  to  account  by  customer  whether  ordered  shipped 
or  not. 

11.  -Where  unruled  paper  is  to  be  cut  and  folded  in  ream 
bundles  or  quarter  ream  and  pound  packages,  the  paper  in  the 
flat  shall  first  be  charged  for  at  the  regular  flat  price.  In  ad¬ 
dition  I  cent  per  pound  shall  be  charged  for  each  pound  of 
pound  packages  shipped,  or  ^  cent  per  pound  for  package  of  a 
quarter  ream  or  more. 

12.  A  charge  of  not  less  than  i^  cents  per  pound  to  be 
made  for  feint  ruling,  such  as  letterheads,  etc.,  and  not  less 
than  2.Y2  cents  per  pound  for  struck  ruling,  such  as  billheads, 
statements,  etc.  This  charge  is  to  apply  on  paper  basis  17  x  22-16, 
and  over;  13  pound  paper  to  be  charged  on  the  basis  of  16  pound, 
and  on  papers  of  less  than  13  pound  weight,  the  charge  to  be 
at  the  option  of  the  mill  doing  the  work. 

13.  There  shall  be  a  minimum  cutting  charge  of  ^  cent 
per  pound  wherever  the  regular  sizes  and  weights  of  unruled 
paper  of  the  mill  are  to  be  cut  to  smaller  sizes. 

(a)  This  minimum  charge  of  3^  cent  per  pound  to  be  made 
when  cutting  any  regular  size  containing  not  less  than  336 


USEFUL  DATA  AND  TABLES  549 

square  inches  (16  x  21)  down  to  and  including  a  size  contain¬ 
ing  not  less  than  84  square  inches  (8  x  io>^)  ;  a  charge  of  i  cent 
per  pound  to  be  made  for  cutting  sheets  containing  less  than 

square  i^he"  *°  '""‘“‘''"S  “  42 

charge  shall  be  the  same 
marker!  are  sealed,  banded  or  merely  divided  by 

14.  Paper  shipped  untrimmed  is  to  be  billed  at  proportionate 
weight  and  there  shall  be  no  allowance  made  for  paper  !n- 

lor’Tor  both“'^  trmmed,  nor  unsealed  instead  of  sealed, 

Paper  such  as  Envelope  paper,  sold  on  basis  of  cut  and  trim 
on  the  machine  to  be  considered  as  trimmed  paper. 

15.  erchants,  manufacturers  or  converters  desiring  special 

customers  must  pay  the  cost  of  dandy  roll 

oMerTd.''"^'^*^  of  cases 

Members  shall  not  sell  private  watermarks  and  brands 

grade^^^  the  same 

ly.  For  weights  lighter  than  basis  sixteen  pounds  17  x  22 
sheets,  an  additional  price  to  be  charged.^  All  Bo!d  and 
Writing  paper  basis  15,  14,  13  pound  folio  to  be  charged  for  at 
ream  prices,  16  pound  basis.  ^ 

18.  New  orders  for  Bonds  and  Linens,  Flat  Writings  and 

Tn  manufactured  only  in  confSmhv 

with  the  following  list  of  substances  on  pages  148  and  140  ^ 

addhkyn''?!T'-^”''^  merchandising,  reams  will  be  marked  (in 
addition  to  their  respective  substances)  with  their  approximate 

PaS!^  Tmde^^A  ^  being  that  compiled  by  the  National 

date  of  rprii  ° 

The  substance  rnay  be  omitted  from  the  reams  on  private 
watermarks  or  brands,  if  so  requested  by  the  owner  thereof. 
u'  n  substances  carry  same  ream  price  as  next 

bdow*^  1^6  Custom  No.  17  governs  on  substances 

(b)  Trade  Custom  No.  i  governs  on  Odd  sizes. 

^ou\v\n  ITl  '918,  this  Trade  Custom  shall 

Writing  Paper  from  above  10  pound 
folio  basis  to  and  including  44  pound  folio  basis.  Exception- 
Orades  below  No.  2  Rag  Envelope.  ^ 


Cover  Papers 

9!^  standard  lines  of  Cover  Papers,  the  following  shall 
e  consKlered^^  sizes  and  substances— all  others  sliall 

be  considered  special. 


550 


MODERN  PULP  AND  PAPER  MAKING 


A,  Regular  Sizes — 

20  X  26 

23  X  33  and  multiples  thereof. 

B.  Regular  Substances — 

20  X  26—25,  35,  40,  so,  65,  80,  90 

23x33—3634, - 73,95, - 

Intermediate  substances  carry  same  ream  price  as  the  next 
higher  substance.  Below  Substance  25  the  same  ream  price  as 
Substance  25. 

Sizes  other  than  20  x  26  made  to  substance  weights  and  figur¬ 
ing  a  fractional  pound  would  be  billed  to  the  nearest  half-pound. 

2.  Any  size  not  listed  in  Paragraph  i  shall  be  interpreted  as 
special.  Special  sizes  may  be  cut  from  standard  size  rolls  in  less 
than  ton  quantities,  but  at  an  additional  price  of  not  less  than 
10  per  cent. 

3.  On  special  colors,  or  colors  not  regularly  made  in  the 
grade  ordered,  ton  lots  not  less  than  15  per  cent  additional  price. 
Less  than  ton  lots  not  less  than  25  per  cent  additional  price. 

4.  On  special  orders  for  one  ton  or  less,  15  per  cent  over- 
or  under-run  to  be  accepted  as  a  commercial  delivery.  On 
orders  for  more  than  one  ton  over-runs  or  under-runs  not  greater 
than  10  per  cent  to  be  accepted  as  a  commercial  delivery. 

5.  Orders  for  less  than  a  full  package,  not  less  than  25  per 
cent  additional. 

A  full  package  shall  be  construed  as  that  number  of  sheets 
which  it  is  the  custom  of  the  mill  to  use  in  wrapping  and  selling 
the  item  of  paper  in  question.  When  ordered  in  conjunction 
with  a  full  package,  this  aditional  charge  will  be  made. 

6.  No  paper  to  be  made  one  weight  and  stenciled  another. 
Paper  to  be  marked  by  manufacturers  the  ream  weight  or¬ 
dered,  and  there  shall  be  no  evasion  by  substituting  letters  or 
symbols  for  figures. 

7.  The  average  actual  weight,  including  wrappers,  not  to 
exceed  234  per  cent  above  or  below  the  nominal  weight.  Paper 
within  this  weight  to  constitute  a  good  delivery,  and  to  be  billed 
at  nominal  weight.  The  above  to  be  based  on  items  of  one  size, 
weight  and  color  on  individual  invoices. 

8.  No  claims  allowed  after  paper  is  cut  or  printed. 

Experience  has  shown  that  exceptional  cases  occasionally 

arise  where  the  fault  is  clearly  with  the  mill  and  where  an  abso¬ 
lutely  literal  enforcement  of  rule  No.  8  would  work  an  injustice 
and  hardship  to  the  merchant.  It  is,  therefore,  understood  that 
mills  will  enforce  the  spirit  of  this  rule,  deciding  exceptional 
cases  upon  their  merits  and  according  to  the  rules  of  equity. 


USEFUL  DATA  AND  TABLES 


551 


TABLE  OF  COMPARATIVE  WEIGHTS 


Book  Papers 


— 

25x38 

40 

50 

60 

70 

80 

90 

100 

120 

120 

95 

126 

149 

156 

165 

190 

158 

178 

192 

199 

218 

240 

316 

298 

312 

356 

22x  32.... 

24  X  36.. . . 

25  x38.... 
26x29.... 
25  X  40. . . 
26x  40.... 
28x42.... 
28x44...  . 
29x45... 
29x  52...  . 

30)/^  X  41 ... . 
32x44.... 
33x46...  . 
31  X  44.  . .  . 

35  X  45. . . . 

36  X  48. . . . 
38x50...  . 
41x61.... 
42x56.... 
44  X  56. . . . 
44  X  64. . . . 

30 

36 

40 

32 

44 

50 

52 

64 

53 

60 

64 

63 

66 

72 

80 

106 

100 

104 

120 

37 

45 

50 

40 

55 

62 

65 

80 

66 

74 

80 

79 

83 

90 

100 

132 

124 

130 

148 

44}^ 

55 

60 

48 

63 

66 

74 
t  78 

82 

96 

79 

89 

96 

95 

100 

110 

120 

158 

148 

156 

178 

52 

64 

70 

56 

74 

77 

86 

90 

96 

112 

92 

104 

112 

no 

116 

128 

140 

184 

172 

180 

208 

59H 

73 

80 

63 

84 

88 

99 

104 

no 

126 

105 

119 

128 

126 

133 

146 

160 

210 

198 

208 

238 

82 

90 

72 

95 

in 

117 

124 

144 

118 

133 

144 

149 

164 

180 

236 

222 

234 

266 

74 

91 

100 

79 

105 

no 

124 

130 

137 

158 

132 

148 

160 

157 

166 

182 

200 

264 

248 

260 

296 

Wrapping  Paper  Sizes 


Scale  of  weights  equal  to  2 1  x  36 


24  x36.. 

15 

20 

I2x  18.  . 

4 

5 

15  X  20. . 

5 

7 

18x24.. 

8 

10 

20x  30.. 

10 

14 

22x32.. 

12 

16 

26x  36. . 

16 

22 

30x40.. 

21 

28 

36  X  40. . 

25 

33 

40  X  48.  . 

33 

44 

48x  52. . 

43 

58 

48x  64.. 

53 

71 

25 

30 

35 

40 

6 

8 

9 

10 

9 

10 

12 

14 

13 

15 

18 

20 

17 

21 

24 

28 

20 

24 

29 

33 

27 

33 

38 

43 

35 

42 

49 

56 

42 

50 

58 

67 

56 

67 

78 

89 

72 

87 

101 

116 

89  1 

107 

124  1 

142 

50 

60 

1  70 

80 

13 

15 

18 

20 

17 

21 

24 

28 

25 

30 

35 

40 

35 

42 

49 

56 

41 

49 

57 

65 

54 

65 

76 

87 

69 

83 

97 

Ill 

83 

100 

117 

133 

111 

133 

156 

178 

144 

173 

202 

231  1 

178  1 

213 

249 

284  1 

90 

1  100 

125 

150 

23 

25 

31 

38 

31 

35 

43 

52 

45 

50 

63 

75 

63 

69 

87 

104 

73 

81 

102 

122 

98 

108 

135 

163 

125 

139 

174 

208 

150 

167 

208 

250 

200 

222 

278 

333 

260 

289 

361 

433 

320 

356 

444 

533 

TABLE  SHOWING  REVISED  WEIGHTS  WHICH  THE  NATIONAL  PAPER  TRADE  ASSOCI¬ 
ATION  UNDER  DATE  OF  APRIL  17,  1917,  REQUESTS  THE  MANUFACTURERS  TO 
MARK  ON  REAMS  OF  BONDS  AND  LINENS,  FLAT  WRITINGS  AND  LEDGER  PAPERS 
MADE  TO  SUBSTANCES. 


No.  13 


14  X  34 .  16J^ 

16  X  21 .  11J4 

16  x26 .  14H 

16  x42 .  23 

16J4x21M .  12 

17  x22 .  13 

17  x26 .  15H 

17  x28 .  16J4 

17  X  44 .  26 

17  x56 .  33 

17Hx22H .  14 

18  x23 .  14H 

18  x  46 .  29 

19  x24 .  16 

19  x26 .  17 

19  x28 .  18^ 

19  X  30 .  20 

19  X  48 .  32 

191^x24^ .  16 

19Mx28J^ .  19 

20  x  28 .  19K 

20  X  56 .  39 

21  x32 .  23 

21  x33 . .  24 

2154x31^ .  23J4 

22  x  25M .  19M 

22  x  34 .  26 

22  x  38 .  29 

22V^x22H .  17H 

22}4x28^ .  22}^- 

221^x  34 .  2614 

22^x2534 .  20J4 

22^x3514 .  28 

23  x  24I4 .  1914 

23  X  28 .  2214 

23  x31 .  25 

23  x  34 .  27 

23  x  36 .  29 

23K  X  28J4 .  23 

24  x  38 .  32 

24  x  48 .  40 

24Hx24J4 .  21 

2414x2814 .  2454 

24V^x  29 .  24J4 

2434  x  3654 .  31 

2434  x  3834 .  33 

26  x  32 .  29 

26  x  33 .  30 

26  x  34 .  31 

26  X  38 .  34 

27  x  40 .  3734 

28  x  34 .  33 

28  x  38 .  37 

28  X  40 .  39 

28  x  4234 .  4134 

30  X  38 .  40 

31  x53 .  57 

34  x  44 .  52 


SUBSTANCE 


<ro.  16 

No.  20 

No.  24 

No.  28 

2034 

2534 

3034 

3534 

143^ 

18 

2134 

25 

18 

22 

2634 

31 

29 

36 

43 

50 

15 

1834 

22 

26 

16 

20 

24 

28 

19 

2334 

2834 

33 

2034 

2534 

3034 

3534 

32 

40 

48 

56 

41 

51 

61 

71 

173^ 

2134 

26 

30 

173^ 

22 

2634 

31 

35 

44 

53 

62 

193^ 

2434 

2934 

34 

21 

2634 

3134 

37 

23 

2834 

34 

40 

2434 

3034 

3634 

4234 

39 

49 

59 

68 

20 

25 

30 

35 

2334 

2934 

35 

41 

24 

30 

36 

42 

48 

60 

72 

84 

29 

36  * 

43 

50 

2934 

37 

4434 

52 

29 

36 

4334 

5034 

24 

30 

36 

42 

32 

40 

48 

56 

36 

4434 

5334 

6234 

2134 

27 

3234 

38 

2734 

3434 

41 

48 

3234 

41 

49 

5734 

25 

3134 

3734 

44 

3434 

43 

52 

6034 

24 

30 

36 

42 

2734 

3434 

4134 

48 

3034 

38 

4534 

5334 

3334 

42 

50 

5834 

35 

44 

53 

62 

2834 

3534 

4234 

4934 

39 

49 

59 

68 

4934 

6134 

74 

86 

2534 

32 

3834 

45 

30 

3734 

45 

5234 

3034 

38 

4534 

53 

3834 

48 

5734 

67 

4034 

5034 

6034 

7034 

36 

44 

53 

62 

3634 

46 

55 

64 

38 

47 

57 

66 

42 

53 

63 

74 

46 

58 

6934 

81 

41 

51 

61 

71 

46 

57 

68 

80 

48 

GO 

72 

84 

51 

6334 

7634 

89 

49 

61 

73 

85 

7034 

88 

10534 

123 

64 

80 

96 

112 

552 


No.  32 

No.  36 

No.  40  No.  44 

4034 

46 

51 

56 

2834 

3234 

36 

3934 

3534 

40 

4434 

49 

57 

65 

72 

79 

2934 

33 

37 

4034 

32 

36 

40 

44 

38 

4234 

4734 

52 

4034 

46 

51 

56 

64 

72 

80 

88 

81 

92 

102 

112 

3434 

39 

43 

4734 

3534 

40 

4434 

4834 

71 

80 

89 

97 

39 

44 

49 

5334 

4234 

4734 

53 

58 

4534 

51 

57 

6234 

49 

55 

61 

67' 

78 

88 

93 

107 

40 

45 

50 

55 

47 

53 

5834 

6434 

48 

54 

60 

66 

96 

108 

120 

132 

57 

65 

72 

79 

5934 

6634 

74 

8134 

58 

65 

7234 

7934 

48 

54 

60 

68 

64 

72 

80 

88 

7134 

8034 

8934 

9834 

4334 

4834 

54 

5934 

55 

6134 

6834 

7534 

6534 

7334 

82 

90 

50 

5634 

6234 

69 

69 

7734 

8634 

95 

48 

54 

6034 

6634 

55 

62 

69 

76 

61 

6834 

76 

84 

67 

7534 

8334 

92 

71 

80 

89 

97 

5634 

64 

71 

78 

78 

88 

98 

107 

9834 

111 

123 

13534 

5134 

58 

64 

7034 

5934 

67 

7434 

82 

61 

6834 

76 

8334 

7634 

86 

9534 

105 

8034 

91 

101 

111 

71 

80 

89 

98 

7334 

8234 

92 

101 

76 

85 

95 

104 

85 

95 

106 

116 

9234 

104 

11534 

127 

81 

92 

102 

112 

91 

102 

114 

125 

96 

108 

120 

132 

102 

11434 

12734 

140 

98 

110 

122 

134 

14034 

158 

17534 

19334 

128 

144 

160 

176 

USEFUL  DATA  AND  TABLES 


553 


AVERAGE  COST  OF 


PRODUCTION  PER  TON  OF  PAPER  FOR  39PRTMrTPAT 
book-paper  mills.  1915  AND  1916  ^9  PRINCIPAL 


1915 

9 

1916 

Increase 
1916  ove 
1915 

Per  cent 
r  of 

increase 

Tons  produced .  .  . , , 

772,532 

Stock: 

Soda  pulp . 

127,630 

19.79 

$14.30 

Sulphite . 

•  .  Uo 

$1.22 

9.33 

Waste  paper . , , 

17.01 

18.81 

1.80 

10.58 

Fillers . , 

•  0 . 79 

7.65 

1.86 

32.12 

Alum . , ,  1 

2.28 

2.21 

L07 

13.07 

Rosin . . 

.  68 

.84 

.16 

23.53 

Color . 

.48 

.72 

^  .24 

50.00 

Miscellaneous.  .... 

.24 

.48 

.24 

100.00 

1 . 12 

1.61 

.49 

43.75 

Conversion: 

Labor . 

40.68 

46.62 

5.94 

14.60 

9.63 

Fuel . 

8. 68 

.95 

10.94 

Repairs . 

2.88 

3.25 

.37 

12.85 

Wires,  felts,  belting,  and  lubricants 

1 .09 

1.31 

1 . 56 
1.43  1 

1.03 

11.89 

Packing  and  shippine . . . 

.12 

9.16 

Miscellaneous . 

1 . 58 

.16 

11.27 

1  29 

1 . 52 

.23 

17.83 

General  expense: 

Taxes  and  insurance .  . 

17.17 

18.97 

1.80 

10.48 

.73 

Administrative.  . . ,  , , 

.04 

5.80 

1 .  /u 

1.80 

.10 

5.88 

i.  0  td,I 

2.39 

2.53 

.14 

5.86 

Factory  cost,  without  depreciation 

Depreciation . 

60.24 

2.00 

68.12 

1.75 

7.88 

1.25 

13.08 

112.50 

lotal  cost . 

62.24 

69.87 

7.63 

12.26 

*  Decrease, 


554 


MODEB-N  PULP  AND  PAPER  MAKING 


PERCENTAGE  OF  TOTAL  COST  OF  PRODUCING  PAPER  OF  39  PRINCIPAL 
BOOK-PAPER  MILLS  ATTRIBUTABLE  TO  PARTICULAR  ITEMS.  1915  AND 
1916, 


\ 

1915 

1916 

Increase 
1916  ov?r 
1915 

644,902 

772,532 

127,630 

Stock: 

Per  cent. 
21.02 

Per  cent. 
20.47 

Per  cent. 
10.55 

27.33 

26.92 

1.41 

9.30 

10.95 

1.65 

3.66 

3.16 

1.50 

1.09 

1.20 

.11 

.77 

1.03 

.26 

.39 

.69 

.30 

1.80 

2.31 

.51 

65.36 

66.73 

1.37 

Conversion: 

13.95 

13.78 

1.17 

Fuel  . 

4.63 

4.65 

.02 

2.55 

2.23 

1.32 

2.10 

2.05 

1.05 

2.28 

2.26 

1.02 

2.08 

2.18 

.10 

27.59 

27.15 

1.44 

General  expense: 

1.11* 

1.04 

1.07 

2.73 

2.58 

1.15 

3.84 

3.62 

1.22 

96.79 

97.50 

.71 

Depreciation . 

3.21 

2.50 

1.71 

100.00 

100.00 

1  Decrease, 


USEFUL  DATA  AND  TABLES 


555 


1915 


Mill 

number 


Stock 

Soda 

pulp 

Sul¬ 

phite 

Waste 

paper 

Mis¬ 

cella¬ 

neous 

Total 

Conversion 


$15,37 

13.24 


$13.66 

19.32 


$2.41 


5.74 


3 . 

82 

21.00 

7.51 

8.74 

16.97 

15.37 

18.29 

19.86 

4.  .  .  . 

5.  .  .  . 

6.  .  .  . 

1.1  34 

7.  .  . 

IS  /IQ 

8 . 

9.  .  . . 

17.20 

5.78 

10. . .  . 

11.  .  .  . 

13.27 

22.69 

12. . .  . 

13. . .  . 

6.77 

14.06 

14.  .  .  . 

12.16 

19.18 

15. . .  . 

35.67 

16 . 

32.88 

2.37  I 

17. . . . 

5.72 

16.59 

18 . 

4.80 

11.48 

19.  . 

28.73 

6.66 

20 . 

20.91 

11.36 

21.  .  . 

16.91 

10.35 

22. . . . 

23 . 

12.11 

17.22  . 

24 ...  . 

12.90 

29.52 

25 . 

16.84 

13.05* 

26 . 

1.27 

16.66 

27 . 

4.98 

12.46 

28 . 

29. . . . 

16.59 

12.69 

30 . 

8.78 

17.95 

31 . 

32 . 

4.06 

25.75  1 

33 . 

18.59 

14.67 

34 ...  . 

15.27 

17.08  1 

35 . 

14.20 

15.04  1 

36 . 

12.96 

14.76 

37 . 

9.00 

17.91 

38 . 

11.38 

25.14 

39 . 

11.62 

L7.78 

4.25 

.23 


4.19 

26.10 

.12 

9.70 

14.27 


$3.55 

3.65 

2.66 

3.43 
3.13 

3.44 
4.11 
3.85 
7.76 
5.33 
3.61 
5,56 
3.99 


$34.99 

36.21 

36.22 
36.62 
35.49 
38.00 
38.14 
39,34 
37.59 
33.64 
39.69 
37.66 
39.09 


Mis- 

Labor  |  cella- 
neous 


Total 


$6.38 

5.84 

5.32 

6.07 

7.65 

7.86 

7.77 

7.22 

7.20 

12.70 

9.08 

7.74 

12.26 


$5.11 


Ceneral 

ex¬ 

pense, 

includ¬ 

ing 

depre¬ 

ciation 


Total 

cost 


$11-49  I  $3.86 


7.77 

3.98 

43.09 

6.21 

2.15 

4.23 

42.05 

9.44 

2.45 

3.76 

41.46 

10.80 

14.40 

5.88 

42.59 

8.31 

17.67 

4.71 

38.66 

12.04 

2.72 

3.98 

42.09 

'  9.26 

10.44 

3.96 

46.67 

6.32 

13.26 

4.79 

45.31 

8.11 

9.94 

9.05 

40.48 

10.46 

4.81 

34.14 

17.65 

.05 

5.35 

47,82 

7.09 

11.70 

4.62 

46.21 

•8,79 

20.26 

5.74 

43,93 

10.81 

19.84 

5.68 

42.96 

11.39 

Average.  13.08 


17.01 


9.19 

9.75 

13.18 

.36 


.60 

.43 


5.79 


3.88 

5.68 

6.75 

8.87 

4.77 

8.61 

5.47 

4.91 

7.94 

4.32 

8.24 

6.20 


4.80 


42.63 

45.40 

42.67 

40.29 

47.76 

42.23 

48.80 

47.21 

44.79 

52.94 

48.36 

40,03 


40.68 


11.40 

11.73 

13.76 
15.24 

8.89 

12.22 

11.76 
11.96 

6.67 

8.98 

12.29 

19.66 


5.41 

11.25 

3.7 

5.90 

11.22 

4.6 

7.39 

13.46 

3.9 

7.80 

15.45 

3.71 

6.05 

13.91 

4. 1C 

7.53 

15.30 

3.51 

6.29 

13.51 

4.17 

8.83 

16.03 

5.32 

9.72 

22.42 

4.33 

8.28 

17.36 

3.62 

9.30 

17.04 

6.10 

7.02 

19.28 

3.47 

7.91 

14. 12 

4.91 

7.23 

16.67 

4.03 

6.92 

17.72 

4.09 

8.02 

16.33 

4.44 

6.92 

18.96 

5.79 

8.18 

17.44 

4.02 

6.98 

13.30 

4.17 

7.14 

15.25 

4.08 

10.66 

21.12  1 

4.56 

8.51 

26.16 

6.03 

7.16 

14.25 

4.79 

8.01 

16.80 

4.23 

8.66 

19.47 

4.06 

8.24 

19.63 

5.45 

9.39 

20.79 

5.26 

7.52 

19.25 

4.11 

10.31 
10,80 

10.32 
14.06 
10.34 
12.10 
19.19 
10.77 
12.24 
16.44 


8.68 


8.49 


24.07 
26.04 
19.21 
26.28 
22.10 
24.06 
25.86 
19.75 
24 . 53 
36.10 


17.17 


4.30 

5.19 
4,77 
3.40 
4.26 
4.16 

7.20 
5.90 
8.18 
6.24 


4.39 


$50.34 
51.21 
52.06 
53.99 
54.69 
56.01 
56.95 
57.02 
58.94 
60.39 
60.67 
60.80 
61.84 
62.12 
62.75 
63.27 
63.36 
63.41 
63.55 
64.14 
64.64 
66.16 
66.33 
66.86 
67.24 
67.46 
68.04 
68.68 
68.76 
71.04 
71,52 
71.74 
71.91 
75.16 
75.43  . 
77.85 
78.59 
81.07 
82.37 


62.24 


MODERN  PULP  AND  PAPER  MAKING 


COST  OF  PRODUCTION  PER  TON  OF  PAPER  OF  39  PRINCIPAL  BOOK-PAPER 
MILLS,  BY  MILLS,  1915  AND  1916— Continued 

1916 


Mill 

number 

Stock 

Conversion 

General 

ex¬ 

pense, 

includ¬ 

ing 

depre¬ 

ciation 

Total 

cost 

Soda 

pulp 

Sul¬ 

phite 

Waste 

paper 

Mis¬ 

cella¬ 

neous 

Total 

Labor 

Mis- 

cella- 

■neous 

Total 

1 . 

*28. 

88 

*4. 

74 

S3. 

81 

S37. 

43 

S6. 

72 

S6. 

33 

S13. 

05 

S4.63 

$55.11 

2 . 

16. 

56 

15. 

34 

$2. 

58 

3. 

73 

38. 

21 

7. 

08 

6. 

01 

13. 

09 

3.97 

55.27 

13 

00 

23. 

77 

3. 

41 

40. 

18 

6 

31 

5 

21 

11. 

52 

4.11 

55.81 

A. 

16. 

86 

18. 

58 

3. 

55 

38. 

99 

7. 

55 

7. 

18 

14. 

73 

4.65 

58.37 

6 . 

19. 

51 

13. 

66 

08 

4. 

65 

37. 

90 

9. 

52 

7. 

99 

17. 

51 

3.11 

58.52 

24 

92 

9. 

93 

3. 

53 

38. 

38 

7. 

86 

7 

85 

15. 

71 

4.46 

58.55 

7 . 

14. 

95 

19. 

01 

6 

05 

3. 

66 

43. 

67 

7. 

76 

6 

49 

14 

25 

4.57 

62.49 

32. 

36 

1 

12 

7 

02 

40. 

50 

10 

75 

7 

78 

18 

53 

3.60 

62.63 

9 . 

31 

44 

5. 

79 

61 

4 

88 

42. 

72 

11 

44 

6 

60 

18 

04 

3.51 

64.27 

10 . 

18 

26 

19 

56 

06 

3 

69 

41. 

57 

10 

72 

9 

14 

19 

86 

3.33 

64.76 

11.  .  . . 

20 

83 

8 

80 

9 

53 

39 

16 

7 

93 

12 

00 

19 

93 

5.80 

64.89 

12 . 

7 

95 

25 

86 

11 

52 

3 

56 

48 

89 

6 

42 

7 

29 

13 

71 

4.85 

67.45 

13 . 

13 

66 

28 

66 

39 

6 

46 

49 

17 

8 

09 

8 

48 

16 

57 

4.37 

70.11 

14 . 

26 

52 

10 

90 

11 

84 

4 

21 

53 

47 

6 

23 

7 

46 

13 

69 

3.40 

70.56 

15 . 

4 

82 

14 

92 

22 

75 

5 

57 

48 

06 

11 

51 

7 

04 

18 

55 

5.39 

72.00 

16 . 

20 

78 

12 

29 

15 

91 

5 

66 

54 

64 

7 

99 

7 

50 

15 

49 

3.56 

73.69 

17 . 

5 

10 

28 

35 

8 

47 

9 

33 

51 

25 

7 

29 

10 

58 

17 

87 

4.69 

73.81 

18 . 

27 

76 

13 

54 

3 

32 

4 

60 

49 

22 

11 

45 

9 

61 

21 

06 

3.63 

73.91 

19 . 

10 

70 

26 

89 

9 

64 

4 

33 

51 

56 

7 

91 

9 

30 

17 

21 

5.48 

74.25 

20 . . 

27 

24 

16 

33 

4 

60 

48 

17 

11 

81 

10 

34 

22 

15 

4.50 

74.82 

21  .  . 

25 

90 

14 

06 

8 

18 

48 

14 

13 

07 

10 

35 

23 

42 

3.78 

75.34 

22 .  . 

20 

38 

19 

18 

6 

46 

46 

02 

12 

68 

12 

48 

25 

16 

4.26 

75.44 

23 . 

10 

59 

18 

22 

15 

18 

6 

81 

50 

80 

11 

06 

10 

62 

21 

68 

3.36 

75.84 

24 .  . 

1 

62 

42 

64 

5 

53 

49 

79 

12 

87 

10 

87 

23 

74 

3.88 

77.41 

25 . 

5 

42 

19 

11 

23 

25 

5 

03 

52 

81 

11 

96 

9 

78 

21 

74 

3.05 

77.60 

26 . 

20 

83 

14 

03 

33 

12 

86 

48 

05 

13 

61 

13 

57 

27 

18 

3.02 

78.25 

27 . 

7 

14 

18 

01 

24 

33 

6 

07 

55 

55 

9 

47 

9 

95 

19 

42 

3.38 

78.35 

28 . 

20 

01 

17 

80 

14 

35 

4 

84 

57 

00 

9 

20 

8 

75 

17 

95 

3.47 

78.42 

29 . 

16 

29 

17 

32 

14 

51 

6 

33 

54 

45 

13 

.23 

8 

34 

21 

57 

3.69 

79.71 

30 . 

1 

50 

20 

80 

25 

07 

6 

94 

54 

31 

12 

.77 

10 

.42 

23 

19 

3.69 

81.19 

31 . 

17 

.56 

15 

31 

17 

88 

5 

36 

56 

11 

11 

.53 

10 

58 

22 

11 

3.51 

81.73 

32 . 

8 

.75 

39 

95 

.84 

6 

17 

55 

71 

9 

90 

11 

82 

21 

.72 

4.72 

82. 15 

33 . 

18 

.17 

19 

.16 

13 

42 

6 

66 

57 

41 

11 

.27 

11 

.06 

22 

33 

3.42 

83.16 

34 . 

6 

.94 

15 

.79 

26 

.50 

8 

04 

57 

27 

14 

.05 

10 

.07 

24 

.12 

5.18 

86.57 

35 . 

14 

.36 

26 

.77 

2 

.12 

9 

92 

53 

17 

14 

.04 

13 

.32 

27 

.36 

7.75 

88.28 

36 . 

17 

.73 

19 

.31 

3 

.57 

5 

99 

46 

60 

17 

.08 

18 

.22 

35 

.30 

6.57 

88.47 

37 . 

23 

.21 

24 

.40 

6 

03 

53 

64 

16 

.04 

14 

.50 

30 

.54 

5.40 

89., 58 

38 . 

5 

.12 

29 

.06 

21 

.79 

5 

.26 

61 

23 

10 

.59 

11 

.53 

22 

.12 

8.86 

92.21 

39 . 

15 

.79 

21 

.70 

12 

.33 

8 

.92 

58 

74 

11 

.52 

19 

.58 

31 

.10 

7.48 

97.32 

Average. 

14 

.30 

18 

.81 

7 

.65 

5 

.86 

46 

.62 

9 

.63 

9 

.34 

18.97 

4.28 

69.87 

USEFUL  DATA  AND  TABLES 


557 


average  cost  op  production  per  ton  op  coated  paper  POR  6  COAT 

ING  MILLS.  1915  AND  1916  '  GOAT- 


1915 

1916 

Increase, 
1916  ove: 
1915 

Per  cent 
of 

increase 

Tons  produced . 

100,920 

— - 

Stock: 

Paper . 

•  0.5, UJ4 

17,896 

21.56 

S.53 . 58 

!  Clay . 

S11.04 

25.95 

Casein . , , 

3.26 

3.25 

1.01 

1.31 

Satin  white.  .  . . 

7.56 

9.68 

2.12 

28,04 

Miscellaneous. . , , , 

1 .  yj 

1.73 

1.19 

11.90 

4.77 

2.18 

84.17 

Conversion : 

Labor . 

57.87 

73.01 

15.14 

26.16 

11.63 

“■ 

Fuel  . 

y .  75 

1.88 

19.28 

Repairs . , 

2.01 

2.06 

.05 

2.49 

Belting  and  lubricants .  . 

i .  4o 

1 . 52 

.12 

.09 

6.29 

Packing  and  shippin? . . 

2.72 

Miscellaneous. . . . , , 

3.01 

.29 

10.66 

.  ol 

.25 

1.06 

1  19.35 

General  expense: 

Taxes  and  insurance.  . . . 

16.34 

18.59 

2.25 

13.77 

.53 

2.02 

Administrative.  .  . ,  , 

.04 

8.16 

♦ 

.48 

31.17 

Total . 

2.03 

2.55 

.52 

25.62 

Factory  cost,  without  deoreciatinn 

76.24 

1.75 

17.91 

1.25 

Depreciation . 

y4 . 15 

1.50 

23.49 

14.29 

Total  cost . 

77.99 

95.65 

17.66 

22.64 

*  Decrease. 


558 


MODERN  PULP  AND  PAPER  MAKING 


PERCENTAGE  OF  TOTAL  COST  OF  PRODUCING  COATED  PAPER  OF  6  MILLS 
ATTRIBUTABLE  TO  PARTICULAR  ITEMS.  1915  AND  1916 


1915 

1916 

Increase, 
1916  over 
1915 

Tons  produced . 

83,024 

100,920 

17,896 

Stock: 

Per  cent. 

Per  cent. 

Per  cent. 

54.55 

56.02 

1.47 

Clay . 

4.18 

3.40 

1  .78 

9.69 

10.12 

.43 

Satin  white . 

2,46 

1.81 

1  .65 

Miscellaneous . 

3.32 

4.98 

1.66 

Total . 

74.20 

76.33 

2.13 

Conversion: 

Labor . 

12.50 

12.16 

1  .34 

Fuel . 

2.58 

2.15 

1  .43 

Repairs . 

1.83 

1.59 

1  .24 

Belting  and  lubricants . 

.15 

.13 

1  .02 

Packing  and  shipping . 

3.49 

3.15 

1  .34 

Miscellaneous . 

.40 

.26 

1  .14 

Total . 

20.95 

19.44 

1  1.51 

General  expense: 

Taxes  and  insurance . 

.63 

.,55 

1  .08 

Administrative . 

1.98 

2.11 

.13 

Total . • . 

2.61 

2.66 

.05 

Factory  cost,  without  depreciation . 

97.76 

98.43 

.67 

Depreciation . 

2.24 

1.57 

1  .67 

Total  cost . 

100 . 00 

100.00 

0.00 

1  Decrease. 


USEFUL  DATA  AND  TABLES 


559 


average  cost  op  ^oduction  per  ton  op  soda  pulp  for  16  MILLS, 


1915 

1916 

Increase 
1916  ove 
1915 

Per  cent 
of 

increase 

Tons  produced .... 

319,623 

Stock: 

Wood.  . 

.  -s()0,8(J7 

52,816 

19.80 

$13.46 

Soda  ash  and  soda. .  . 

$13. 24 

$0.22 

1.66 

Bleach . 

2.38 

.40 

20.20 

Lime. . . ,  , 

3.07 

2.89 

L18 

•5.86 

Miscellaneous^^_j_^_^^^^__ 

1 . 90 

1.99 

.09 

4.74 

.  Uo 

.08 

.03 

60.00 

Conversion: 

Labor. .  .  , 

20.24 

20.80 

.56 

2.77 

5.96 

Fuel . 

o .  29 

.67 

12.67 

Repairs.  . 

4.03 

4.48 

.45 

11.17 

Felts,  wires,  belting,  and  lubricants. 

1 .45 

.31 

1.73 

.33 

.28 

19.31 

Miscellaneous.  .  . , 

.02 

6.45 

.  7o 

.81 

.05 

6.58 

i.  OtSl . . . 

General  expense: 

Taxes  and  insurance .  .  , 

11.84 

13.31 

1.47 

12.42 

.41 

Administrative 

.01 

2.50 

1 .  Oo 

1.20 

.12 

11.11 

1-  0  .  ,1.,,. . .  ^ 

1.48 

1.61  1 

.13 

8.78 

Factory  cost,  without  depreciation 

Depreciation . 

33.56 

1.50 

35.72 

1.25 

2.16 

1.25 

'  6.44 

1 16.67 

Total  cost . 

35.06 

36.97 

1.91 

5.45 

1  Decrease. 


560 


MODERN  PULP  AND  PAPER  MAKING 


PERCENTAGE  OF  TOTAL  COST  OF  PRODUCING  SODA  PULP  OF  16  MILLS 
ATTRIBUTABLE  TO  PARTICULAR  ITEMS,  1915  AND  1916 


1915 

1916 

Increase, 
1916  over 

1915 

Tons  produced . 

266,807 

319,623 

52,816 

Stock: 

Per  cent. 

Per  cent. 

Per  cent. 

37.76 

30.41 

1  1.35 

Soda  ash  and  soda . 

5.65 

6.44 

.79 

Bleach . 

8.76 

7.82 

I  .94 

Lime . 

5.42 

5.38 

1  .04 

Miscellaneous . 

.14 

.21 

.07 

Total . 

57.73 

56.26 

I  1.47 

Conversion: 

Labor . 

15.09 

16.12 

1.03 

Fuel . 

11.49 

12.12 

.63 

Repairs . 

4.14 

4.68 

.54 

Felts,  wires,  belting,  and  lubricants . 

.88 

.89 

.01 

Miscellaneous . 

2.17 

2.19 

.02 

Total . 

33.77 

36.00 

2.23 

General  expense: 

Taxes  and  insurance . 

1.14 

1.11 

1  .03 

Administrative . 

3.08 

3.25 

.17 

Total . 

4.22 

4.36 

.14 

Factory  cost,  without  depreciation . 

95.72 

96.62 

.90 

Depreciation . 

4.28 

3.38 

1  .90 

Total  cost . 

100.00 

100.00 

0.00 

1  Decrease. 


USEFUL  DATA  AND  TABLES 


561 


average  cost  of  production  per  ton  op  sulphite  for  9  MILLS, 


1915 

1916 

Increase, 
1916  over 
1915 

Per  cent 
of 

increase 

Tons  produced . 

179,419 

203,003 

23,584 

13.14 

Stock: 

Wood . 

$18.87 

2.71 

3.11 

.48 

.01 

$18.80 

2.56 

3.15 

.48 

.28 

>$0.07 
>  .15 
.04 
.00 
.27 

>0.37 

>5.54 

1.29 

.00 

2,700.00 

Sulphur  and  pyrites. . 

Bleach . 

Lime . 

Miscellaneous.  .  ,  , 

Total . 

25.18 

25.27 

.09 

.36 

Conversion: 

Labor . 

5.54 

2.73 

1.58 

.36 

.72 

5.65 

2.84 

1.59 

.39 

.75 

.11 

.11 

.01 

.03 

.03 

1.99 

4.03 

.63 

8.33 

4.17 

Fuel .  1 

Repairs . 

Felts,  wires,  belting,  and  lubricants.  .  . 

Miscellaneous.  .  .  . 

Total . , 

10.93 

11.22 

.29 

2.65 

General  e.xpense: 

Taxes  and  insurance .  .  . 

.43 

1.08 

.51 

1.87 

.08 

.79 

18.60 

73.15 

Administrative.  .  , , 

Total . 

1.51 

2.38 

.87 

57.62 

Factory  cost,  without  deDreciatinn 

Depreciation . 

37.62 

1.50 

38.87 

1.25 

1.25 

>.25 

3.32 
> 16.67 

Total  cost .... 

. 

39.12 

40.12  1 

1 

1.00 

2.56 

Decrease. 


562  MODERN  PULP  AND  PAPER  MAKING 


PERCENTAGE  OF  TOTAL  COST  OF  PRODUCING  SULPHITE  OF  9  MILLS  ATTRI¬ 
BUTABLE  TO  PARTICULAR  ITEMS,  1915  AND  1916 


1915 

1916 

Increase, 
1916  over 
1915 

Tons  produced . 

179,419 

203,003 

23,584 

Stock: 

Per  cent. 

Per  cent. 

Per  cent. 

Wood . 

48.24 

46.86 

1  1.38 

Sulphur  and  pyrites . 

6.93 

6.38 

1  .53 

Bleach . 

7.95 

7.85 

1  . 15 

Lime . 

1.23 

1.20 

1  .00 

Miscellaneous . 

.02 

.70 

.68 

Total . 

64.37 

62.99 

1  1.38 

Conversion: 

Labor. .  . . 

14.16 

14.08 

»  .08 

Fuel . 

6.98 

7.08 

.10 

Repairs . 

4.04 

3.96 

1  .08 

Felts,  wires,  belting,  and  lubricants . 

.92 

.97 

.05 

Miscellaneous . 

1.84 

1.87 

.03 

Total . 

27.94 

27.96 

.02 

General  expense: 

Taxes  and  insurance . 

1.10 

1.27 

.17 

Administrative . 

2.76 

4.66 

1.90 

Total . 

3.86 

5.93 

2.07 

Factory  cost,  without  depreciation . 

96.17 

96 . 88 

.71 

Depreciation . 

3.83 

3.12 

1  .71 

Total  cost . 

100.00 

100.00 

0.00 

'  Decrease. 


USEFUL  DATA  AND  TABLES 


563 


OF  PRODUCING  NEWS-PRINT  PAPER  ATTRTR 
UTABLE  TO  PARTICULAR  ITEMS  -  UNITED  STATES  AND 
mills  combined  —  1913-1916  (FIRST  HALF)  CANADIAN 


Item 


Stock . 

Sulphite . 

Ground  wood . 

Fillers . 

Alum . 

Sizing . 

Miscellaneous . 

Total . 

Conversion: 

.  Labor. . 

Felts . 

Wires . ; . 

Belting . 

Lubricants . 

Repairs . 

Fuel . 

Power  and  water  rentals. . . 
Miscellaneous . 

Total . 

General  expense: 

Taxes  and  insurance . 

General  and  administrative 

Total . 

Depreciation . 

Total  cost . 


1913 


Per  cent. 
24.41 
34.71 
1.18 
.52 
.  35 
1.72 


62.89 


10.20 

2.57 

1.16 

.28 

.26 

3.97 

6.39 

.76 

3.37 


28.96 


1.19 

1.82 


3.01 


5.14 


100.00 


1914 


Per  cent. 
23.69 
34.97 
1.14 
.54 
.30 
1.85 


62.49 


10.17 

2.48 

1.08 

.33 

.26 

3.91 

6.36 

.90 

3.55 


29.04 


1.36 

1.92 


3.28 


5.19 


100.00 


1915 


Per  cent. 

23.66 

34.67 
1.20 

.63 

.28 

2.26 


02.70 


10.16 

2.35 
1.24 

.30 

.25 

3.29 

6.35 
1.14 
3.56 


28.64 


1.18 

2.00 


3.18 


5.48 


100 . 00 


First  half 
1916 


Per  cent. 

23.30 

34.30 
.80 
.  63 
.21 

1.90 


01.26 


.999 

2.51 

1.36 

.30 

.22 

3.54 

7.28 

1.08 

3.00 


29.88 


1.33 

1.96 


3.29 


5.57 


100.00 


564  MODERN  PULP  AND  PAPER  MAKING 


COST  OF  MANUFACTURE  PER  TON  OF  NEWS-PRINT  PAPER  FOR  PRINCIPAL 
UNITED  STATES  MILLS,  1915-1916  (FIRST  HALF) 


Stock 

Total 

General 

expenses 

Mill  No. 

1 

Sulphite 

Ground 

wood 

Miscella 

neons 

Total 

conver¬ 

sion 

Depreci¬ 

ation 

Total 

cost 

115: 

1 . 

$7.23 

$9.00 

$1.62 

$17.85 

$5.06 

$1.11 

$1.75 

$25.77 

2 . 

6 . 52 

8,96 

.61 

16.09 

8.46 

.38 

1.75 

26.68 

3 . 

8.18 

8.73 

1.65 

18.56 

5.55 

1.08 

1.75 

26.94 

4 . 

6.90 

8.59 

.68 

16.17 

9.21 

.39 

1.75 

27.52 

5 . 

6.36 

10.85 

1.80 

19.01 

7.78 

.77 

1.74 

29.30 

6 . 

7.48 

10.26 

1.25 

18.99 

7.77 

1.97 

1.72 

30.45 

7 . 

7.20 

11.17 

1.42 

19.79 

8.42 

.90 

1.48 

30.59 

8 . 

5.39 

12.78 

1.52 

19.69 

8.43 

1.20 

1.49 

30.81 

9 . 

6.69 

12.46 

1.43 

20.58 

7.41 

1,55 

1.48 

31.02 

10 . 

9.22 

12.35 

1.59 

23.16 

6.27 

1.17 

1.45 

32.05 

11 . 

7.02 

10,70 

.31 

18.03 

10.95 

1.38 

1.75 

32.11 

12 . 

6.82 

11.45 

1.61 

19.88 

9.95 

.64 

1.75 

32,22 

13 . 

7.08 

12.33 

.74 

20.15 

10.24 

.51 

1.75 

32.65 

14 . 

4.91 

11.56 

1.40 

17.87 

12.25 

1.34 

1.75 

33.21 

15 . 

5.94 

11.43 

1.59 

18.96 

11.51 

1.23 

1.75 

33.45 

16 . 

7.03 

14.37 

2.08 

23.48 

8.16 

.60 

1.66 

33.90 

17 . 

6.10 

14.03 

1.65 

21.78 

10.12 

.87 

1.71 

34.48 

18 . 

8.55 

12.70 

.77 

22.02 

8.99 

1.82 

1.75 

34.58 

19 . 

8.16 

12.68 

2.28 

23.12 

8.93 

1.41 

1.64 

35.10 

20 . 

6.06 

13.07 

2.04 

21.17 

11.15 

1.09 

1.74 

35.15 

21 . 

8.40 

10,53 

.82 

19.75 

11.77 

1.90 

1.75 

35.17 

6.93 

16.03 

2.01 

24.97 

8.01 

.69 

1.53 

35.20 

23 . 

6.72 

15.41 

1.58 

23.71 

8.85 

1.04 

1.69 

35.29 

24 . 

6.80 

13.18 

1.80 

21.78 

11.34 

.99 

1.74 

35.85 

25 . 

10.04 

11.78 

2.69 

24.51 

8.77 

1.37 

1.41 

36.06 

26 . 

6.61 

14.87 

1.70 

23.18 

10.73 

1.12 

1.75 

36.78 

27 . 

9.13 

14.09 

3.07 

26.29 

8.22 

.99 

1.49 

36.99 

28 . 

8.59 

14.03 

.83 

23.45 

10.81 

1.34 

1.40 

37.00 

9.44 

11.70 

1.57 

22.71 

11.05 

1.97 

1.37 

37.10 

30 . 

8.52 

13.79 

.90 

23.21 

10.64 

1.64 

1.75 

37.24 

31 . 

7.79 

12.75 

1.58 

22.12 

11.38 

2.72 

1.46 

37.68 

32 . 

12.44 

12.78 

1.63 

26.85 

8.85 

1.80 

1.64 

39.14 

33 . 

4,55 

16.63 

2,43 

23.61 

13.35 

1.84 

1.75 

40.55 

34 . 

8.44 

14.43 

2.19 

25.06 

14.37 

1.57 

1.75 

42.75 

35 . 

10.69 

13.73 

.90 

25.32 

16.18 

1.16 

1.75 

44.41 

Average. 

7.47 

11.63 

1.39 

20.49 

9.00 

1.03 

1.69 

32.21 

USEFUL  DATA  AND  TABLES 


565 


COST  OF  manufacture  PER  TON  OF  NEWS-PRINT  PAPER  FOR  PRINCIPAL 
UNITED  STATES  MILLS.  1915-1916  (FIRST  HALF)— Continued 


Stock 


Mill  No. 

Sulphit 

Grounc 
e  , 

wood 

Miscella 

neous 

Total 

Total 

conver¬ 

sion 

Genera 

expense 

Deprec 
s  ation 

i-  Total 
cost 

1916  (first  half) 
1 . 

$7.70 

$8.18 

$1.21 

$17.09 

$5.36 

$.73 

$1.75 

$34.93 

7.41 

8.71 

1.27 

17.39 

5.96 

.71 

1.75 

25.81 

0 . 

6.70 

9.08 

.04 

15.82 

9.31 

.50 

1.75 

27.38 

4 . 

7.51 

8,39 

.91 

16.81 

9.13 

.52 

1.75 

28.21 

5 . 

6.13 

11.35 

1.51 

18.99 

6.30 

1.90 

1.49 

28.68 

6 . 

6.48 

10.67 

1.07 

18.22 

8.17 

.82 

1.74 

28.95 

4 . 

8 . 

4.32 

13.87 

.74 

18.93 

7.93 

2.03 

1.45 

30.34 

7. 12 

8.80 

.22 

16.14 

10.73 

1.75 

1.75 

30.37 

y . 

10 . 

5 . 82 

13.44 

1.65 

20.91 

7.43 

1.27 

1.48 

31.09 

6.95 

9.81 

1.71 

18.47 

9.09 

2.02 

1.75 

31.33 

11  . 

12  . 

13  . 

14  . 

5.87 

11.79 

.90 

18.56 

10.39 

.71 

1.75 

31.41 

8.12  . 

11,00 

.40 

19.52 

8.39 

1.78 

1.75 

31.44 

7,01 

11.30 

.40 

18.71 

11.28 

.74 

1.75 

32.48 

4.80 

12.21 

1.10 

18.11 

11.63 

1.12 

1.75 

32  61 

15 . 

6.71 

10,43 

1.15 

18.29 

11.65 

1.15 

1.75 

32.84 

16 . 

6.61 

11.71 

1.65 

19.97 

9.69 

1.58 

1.75 

32  99 

17 . 

7.72 

13.06 

1.06 

21.84 

8.93 

.79 

1.46 

33.02 

18 . 

6.96 

14.02 

1.42 

22.40 

8.63 

.68 

1.70 

33.41 

19 . 

6,02 

13.74 

1.08 

20.84 

11.14 

.92 

1.75 

34.65 

20 . 

9.49 

11.93 

2.51 

23.93 

8.98 

1.28 

1.34 

35.53 

21 . 

8.02 

14.16 

1.11 

23.29 

9.61 

1.08 

1,75 

35 . 73 

22 . 

7.97 

10.92 

.73 

19.62 

12.66 

1.73 

1.75 

35.76 

23 . 

6.65 

16.55 

1.13 

24.33 

9.04 

.85 

1.56 

35.78 

24 . 

7.93 

13.01 

.51 

21.45 

10.75 

1.84 

1.75 

35.79 

25 . 

8.34 

12.73 

1.33 

22.40 

11.38 

.90 

1.75 

36.43 

26 . 

8.61 

11.69 

2.30 

22.60 

10.68 

1.99 

1.39 

36.66 

27 . 

8.35 

13.37 

.76 

22.48 

11.53 

1.29 

1.38 

36.68 

28 . 

9.52 

12.89 

3.62 

26.03 

8.17 

1.41 

1.49 

37.10 

29 . 

7.67 

12.76 

1.85 

22.28 

12.84 

1.06 

1.75 

37.93 

30 . 

7.39 

14.66 

1.38 

23.43 

12.22 

1.15 

1.75 

38.55 

31 . 

7.04 

13.68 

3.10 

23,82 

12.73 

2.00 

1.48 

40.03 

32 . 

13.07 

11.89 

2.55 

27.51 

9.68 

1.75 

1.69 

40.63 

33 . 

8.75 

15.22 

1.22 

25.19 

15.76 

1.32 

1.75 

44.02 

34 . 

11.32 

16.59 

1.68 

29.59 

14.46 

1.14 

1.75 

46.94 

Average. 

7.33 

11.33 

1.09 

19.75 

9.40 

1.08 

1.70 

31.93 

566  MODERN  PULP  AND  PAPER  MAKING 


PERCENTAGE  OP  TOTAL  COST  OF  PRODUCING  SULPHITE  ATTRIBUTABLE 
TO  PARTICULAR  ITEMS  — UNITED  STATES  AND  CANADIAN  MILLS  COM¬ 
BINED  —  1913-1916  (FIRST  HALF). 


Item 

1913 

1914 

1915 

First 

half 

1916 

Stock: 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Sulphur . 

10.38 

10.35 

10.21 

9.77 

Lime  and  limestone . 

2.65 

2.49 

2.46 

2.39 

Wood . 

54.69 

54.28 

55.53 

56.36 

Total . 

67.72 

67.12 

68.20 

68.52 

Conversion: 

Labor . 

11.32 

11  38 

10.85 

.34 

10.30 

.40 

Felts . 

.31 

.32 

Wires . 

.07 

.06 

.06 

.10 

Belting . 

.39 

.36 

.26 

.32 

Lunbricants . 

.09 

.09 

.09 

.08 

Repairs . 

5.61 

5.43 

5.15 

5.36 

Fuel . • . 

8.20 

7.80 

7.33 

7.77 

Power  and  water  rentals . 

1.24 

2.09 

2.00 

1.91 

Miscellaneous . 

1.84 

1.77 

2.06 

2.01 

Total . 

29.07 

29.30 

28.14 

28.25 

General  expense: 

Taxes  and  insurance . 

1.25 

1.28 

1.24 

1.26 

General  and  administrative . 

1.96 

2.30 

2.42 

1.97 

Total . 

3.21 

3.58 

3.66 

3.23 

Total  cost  ' . 

100.00 

100.00 

100.00 

100.00 

I  Exclusive  of  depreciation, 


USEFUL  DATA  AND  TABLES 


S^7 


COMBINED— 1913-1916  (FIRST  HALF).  STATES  AND  CANADIAN  MILLS 


Item 

1913 

1914 

1915 

First 

half 

1916 

Wood.  . . 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Conversion; 

Labor . 

65.04 

64.86 

67.11 

68.85 

16.11 

Stones. .  .  . 

16.38 

15.00 

14.12 

Felts. . . . 

.86 

.94 

.82 

.92 

Wires . 

.57 

.57 

.55 

.57 

Belting. . .  .  ^ 

.  19 

.19 

.21 

.27 

Lubricants. . 

.45 

.43 

.35 

.34 

Repairs.  .  . 

.22 

.20 

.17 

Power  and  water  rentals 

o .  S3 

5 . 62 
4.21 

5.07 

4.65 

Aliscellaneous.  . 

4.20 

3.98 

J .  1 1 

2.25 

2.43 

2.28 

J. otal .  . . . 

General  expense: 

Taxes  and  insurance 

30,50 

30 . 54 

28.83 

27.30 

1.78 

2.82 

General  and  administrative 

1 .46 

1.49 

2.60 

2.36 

4.46 

4.60 

4.06 

3.85 

total  cost  >. . 

100,00 

100,00 

100.00 

100.00 

— 

.  *  Exclusive  of  depreciation. 


568  MODERN  PULP  AND  PAPER  MAKING 


QUANTITIES  AND  PROPORTIONS  OF  MATERIALS,  EXCLUSIVE  OF  COLORS 
AND  SOME  MISCELLANEOUS  ITEMS.  USED  IN  1916  BY  3  EASTERN  AND  5 
MICHIGAN  COMPANIES. 


/ 

Three  eastern  companies  (pro¬ 
duction,  291,953  tons) 

Five  Michigan  companies  (pro¬ 
duction,  89,015  tons) 

Materials 

Quantity 

Pounds 
used  per 
ton  of 

paper 

produced 

Propor¬ 
tions  of 
materials 
used 

Quantity, 

Pounds 
used  per 
ton  of 
paper 
produced 

Propor¬ 
tions  of 
materials 
used 

Soda  pulp . 

Tons 

138,910 

952 

Per  cent 

40.1 

Tons 

6,949 

156 

Per  cent 
5.7 

Sulphite . 

120,730 

827 

34.9 

26,140 

587 

21.7 

Waste  paper . 

10,063 

69 

2.9 

171,031 

1  1,596 

158.9 

Clay,  agalite  and  talc . 

67,223 

460 

19.4 

9,885 

222 

8.2 

Alum . 

5,980 

41 

1.7 

4,851 

109 

4.0 

Rosin . 

3,310 

23 

1.0 

1,799 

41 

1.5 

Total . 

346,216 

2,372 

100.0 

120,655 

2,711 

100.0 

>  Includes  a  small  proportion  of  rags. 


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‘  Exclusive  of  depreciation  which  on  the  average  would  be  about  SI. 17  per  ton  of  sulphite. 


AVERAGE  COST  OF  MANUFACTURE  PER 


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AMERICAN  PULPWOODS  * 

By  Otto  KkessC  Sidney  D.  Wells^  and  Vance  P.  Edwards^ 


Forest  Products  Laboratory,  Madison,  Wisconsin 

The  Forest  Products  Laboratory,  Madison,  Wis.,  has  in  the  past 
received  frequent  requests  as  to  the  suitability  of  various  woods  for  pulp 
and  paper  production  and  it  has  therefore  seemed  advisable  to  prepare  for 
publication  some  of  the  available  data  on  this  subject  The  laboratory 
has  carried  on  an  extended  investigation  over  a  period  of  more  than  ten 
years  and  has  collected  experimental  pulping  data  on  practically  all  the 
possible  species  of  American  pulp  woods.  These  data,  in  so  far  as  the 
chemical  pulps  are  concerned,  have  mainly  been  obtained  from  experi¬ 
mental  cooks  made  in  the  Forest  Products  Laboratory,  Madison,  Wis., 
in  lOO-pound  semi-commercial  digesters,  and  from  studies  made  on  the 
resulting  pulps.  It  has  been  found,  however,  that  the  general  cooking 
conditions,  yield,  bleach,  consumption,  etc.,  as  determined  by  experimental 
trials  for  pulp  made  from  any  given  wood,  compare  quite  favorably  with 
the  results  obtained  in  commercial  practice.  The  data  for  the  various 
mechanical  pulps  were  obtained  from  the  experiments  carried  on  at  the 
ground-wood  laboratory,  Wausau,  Wis.,  where  a  commercial-sized  grinder 
equipment  was  installed  by  the  Forest  Products  Laboratory  in  co-operation 
with  the  American  Paper  and  Pulp  Association. 

The  yield  of  pulp  from  any  given  wood  depends  directly  upon  the 
specific  gravity  of  the  wood  or  weight  per  cubic  foot,  and  the  pulping 
method  employed.  By  varying  the  severity  of  the  pulping  treatment, 
both  yield  and  bleach  consumption  are  changed.  For  example,  white 
spruce  sulphite  pulp  prepared  for  the  manufacture  of  newsprint  paper 
would  show  an  entirely  different  yield  and  bleach  consumption  from 
bleached  white  spruce  pulp  prepared  for  use  in  a  white  bond  paper. 
It  is,  therefore,  evident  that  the  character  and  use  of  the  pulp  will  largely 
decide  the  severity  of  the  cooking  operation.  Certain  woods,  such  as 
western  larch,  containing  a  high  percentage  of  galactan,  which  is  water- 
soluble,  will  show  a  decreased  yield  by  either  mechanical  or  chemical 
pulping. 

Pulping  data  have  been  given  for  woods  such  as  red  and  white  oak, 
white  ash  and  certain  other  woods  not  because  we  consider  these  species 
suitable  for  pulp  purposes,  but  because  the  information  was  available. 
Many  wood-using  plants  produce  considerable  tonnage  of  slabs  and  mill 
waste  of  woods  not  espetially  suitable  for  pulp  production,  and  are  inter¬ 
ested  in  a  possible  outlet  for  this  waste.  In  some  cases,  at  their  direct 
request,  pulping  trials  have  been  made  on  woods  known  to  be  unsuitable 
for  pulping  purposes.  The  various  woods  have  been  listed,  giving  the 

*  From:  “The  Paper  Industry,”  Chicago,  Ill. 

■*  Much  of  the  data  used  in  this  report  has  been  collected  at  a  previous  date  by 
Henry  E.  Surface  of  our  laboratory,  but  not  for  publication.  We  also  wish  to 
acknowledge  the  contributions  of  Edwin  Sutermeister,  R.  C.  Cooper,  G.  C.  Me- 
Naughton,  C.  K.  Textor  and  S.  E.  I.unack,  who,  while  in  the  employ  of  the  Forest 
Service,  made  some  of  these  cooks. 

“  In  charge.  Section  of  Pulp  and  Paper. 

®  Engineer  in  Forest  Products. 


572 


AMERICAN  PULPIVOODS 


573 

in  use  and  the  Tang^Toteriig  the  growth  o7  tS  "ames 

information  has  been  takeT  directfy  ^  This 

frees  of  the  United  States’-  by'c'eo'rgrB  It, d^wSl, 

a,te„t,;onj1ir^,ts:i^trw:;4''*",,^«^ 

cubic  foot.'^Tfiiris”  obTaTied^'bll'In.d'r  1°'^  bone-dry  material  per  solid 
over-dried  wood  based  on  the  green  vohirne  ^*^*^*^'0*^  gravity  of  the 
of  a  cubic  foot  of  water).  ^  ^  weight 

datJ  ’Sken^'TromTh'^Fo^Tlervke*'-'  “'”>«=>ble 

sources.  Many  of  the  tneasuremenrc  '  ”^'^^®^*§^ations  and  from  other 

of  thousands  of  determinations  •  in  ^  results  of  averages 

terminations.  ^^^ermmations ,  m  other  cases  from  only  a  few  de- 

Heachl^'pSl'pe^KSIe'd  tali?'" 

opinion  that  i,?  general  the  m'linal)  eo.!?'"!  ‘>o.J^=-dry  wood.  It  is  our 
wood  piled  4x4x8  feet  closelv  *■  rossed 

To  convert  the  yields  on  bone  d^v  hask^r^^  joo  solid  cubic  feet  of  wood, 
cent  moisture,  divide  the  yield  by^p  °  air-dry  pulp  containing  10  per 

made  un^der^ very^  favorabk^condklol!?  experimental  runs 

laboratory  are  4rked  sawed  ^’'"'''al  at  the 

taining  kLts  and  deiced  spo  is  rS^^^  T," 

sorted  and  are  far  more  nn;fr.rm  rejected.  1  he  chips  are  carefully 
be  obtained  in  commercial  nJactTee  nnIf  moisture  content  than  can 

favorable  condido'r  than  ordh.  Hl^eSt  V"ur  ,lr°‘’lrl'  ""t'' 
senting  an  individual  experiment  it  is  nossihlf>  fra  ’  1  \ 

!' F£’S“  S-5S-S  ■  S“s'S3 

to  rrors-^f'  'f  ‘)«V'>th.\e"‘Sed“??o^"“';'^t^ 

wood  has  IikevSL“’ble„"’a4.ecft  tlm^TtlndarT  fS'le Jict'S'n  b7?lie 

^No  fimS/bf  compared  wfth  it. 

Pvlo  hgures  have  been  given  on  the  bleaching  of  the  sulohate  mins 

?oumrv'^a%"b°e  n^"°'^h°h-  making  bleached  sulphate  p^ulp  in^  this 

„  1  ^  ^  e  present  time.  By  this  we  do  not  mean  to  imnlv  that  sulohate 

prtticT"°'  ^^°--ically  bleached,  but  this  is  no!  the"  present  mil 

possible  soda  pulping  of  the  various 
firs,  pines,  hemlocks,  larch,  tamarack  and  other  woods  that  can  be  reduced 

trils  laboratory  has  made  extensive  pulphlg 

trials  on  the  reduction  of  these  woods  by  the  soda  process  and  it  is  of 

process  can  be  and  is  at  present  employed  to 
a  limited  extent  for  reduction  of  certain  of  these  woods.  In  gleral 

Drodu1fnrnf^1^b\^^  of  any  wood  suitable  W  the 

wberP  to  be  bleached  and 

wnere  strength  is  of  primary  consideration.  These  soda  pulps  from 

Idea^Senl  Woods  could,  of  course,  through  a  severe  pulping  treatment,  be 
ble^hed  with  a  reasonable  bleach  consumption. 

on  j  °  have  been  given  for  bleach  consumption.  It  has  appeared 

advisable  to  compare  the  ease  of  bleaching  for  any  given  pulp  with  the 
®m^ard  white  spruce  sulphite  and  aspen  soda  pulp. 

+b  f  fif  c  ^  given  must,  of  course,  be  interpreted  with  the  understanding 
that  the  hgures  and  results  are  based  on  experimental  pulping  trials.  We 


574  MODERN  PULP  AND  PAPER  MAKING 

l,elieve  that  it  may  be  of  interest  if  used  with  this  reservation  for  com¬ 
paring  the  character  and  yields  of  pulps  that  may  be  expected  from  dif¥er- 

ent  woods. 

.„'d''’„"rfde»w"’;d  ,o  .he  Mackenzie  r.ver. 
Southward  in  Michigan,  Wisconsin,  Minnesota,  and  in  the  eastern  mountains  to 
North  Carolina  and  Tennessee.  M-d;.;  R  I  NY  Pa  W  Va., 

Cd~..  Sp™„ 

Jaune  (Quebec);  Water  Spruce  (Canada,  Me.). 

Sulphite  Pulp  „  ,  ,  , 

Yield  1,050  lb.  Easily  bleached. 

Easily  pulped — excellent  strength  and  color. 

Possible  Uses — Same  as  white  spruce. 

Sulphate  Pulp 

Character  and  Uses — Similar  to  White  Spruce. 

®"”E.%"e-c7„SYSy’' "fonnS  ?.ln.-Coi;,ado, T.Si  “"f Bah 

Colorado  Blue  Spruce  (Colo.);  Prickly  Spruce  (lit). 

Sulphite  Pulp 

Yield  1,050  lb.  Easily  bleached. 

Easily  pulped — excellent  strength  and  color. 

Possible  Uses — Same  as  white  spruce. 

Sulphate  Pulp 

Yield  1,150  lb- 

Character  and  Uses — Similar  to  white  spru^. 

Engelmann  Spruce— Pica  engelmanni  Wt  21  lb.  ^jber  2  m.  m.  British 

Range — Northern  Arizona  and  through  the  Rocky  Mountain  r  g 

Common  NamM— Engelmann’s  Spruce  (Utah) ;  Balsam 

(Oreg.,  Colo.,  Utah,  Idaho;  White  Pine  (Idaho);  .dountain  Spruce  (Mont.;, 
Arizona  Spruce  (Cal.  lit.). 

Sulphite  Pulp 

Yield  990  lb.  Easily  bleached.  ,  r-  11  ♦  ...izar 

A  little  hard  to  pulp — excellent  strength.  Excellent  color. 

Possible  Uses — Same  as  white  spruce. 

Sulphate  Pulp 

Yield  1,000  lb.  .  . 

Character  and  Possible  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 
Yield  2,100  lb. 

Character — Strong  fiber  of  good  color. 

Possible  Uses — Same  as  white  spruce. 

Red  Spruce — Picea  rubens.  Wt.  24  lb.  Fiber  3-7  m.  m.  r).,r,o-P  Imnerfectlv 

Range— Scotia  to  North  Carolina  and  Tennessee.  Range  impertec  y 

cZTmon  Names-Rtd  Spruce;  Yellow  Spruce  (N.  Y.) ;  North  American  Red 
Spruce  (foreign  lit.). 

Sulphite  Pulp 

Yield  1,080  lb.  Easily  bleached. 

Easily  pulped — good  strength — excellent  color. 

Possible  Uses — Same  as  white  spruce. 

Sulphate  Pulp 

Yield  1,150  lb. 

Character — High-grade  strong  fiber. 

Possible  Uses — Same  as  -white  spruce. 

Mechanical  Pulp 
Yield  2.400  lb. 

Character — Excellent  color  and  strength. 

Possible  Uses — Similar  to  white  spruce.  ^ 

Sitka  Spruce— Picea  sitchensis.  Wt.  24  lb.  Fiber  3-5  Ala«ka  to 

Range — Coast  region  (extending  inland  about  fifty  miles)  from  Alaska 

northern  California  (Mendocino  County).  ,,,  ,  s  •  >  0/,^.,/..,  •  H/t>i;tern 

Common  Names— TideXand  Spruce  (Cal.,  Ore.,  Wash.);  Mensws  Spruce.  IPesteri 

Spruce:  Great  Tideland  Spruce  (Cal.  lit.). 

Sulphite  Pulp 

Yield  1,080  lb.  Easily  bleached. 

Easily  pulped - excellent  strength  and  color. 

Possible  Uses — Same  as  white  spruce. 

Sidphate  Pulp 

Yield  1,150  lb. 

Character  and  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 

Yield  2,040  lb. 


AMERICAN  PULPWOODS 


575 


Character— Slightly  grayish  color. 

Similar  to  white  spruce 

White  Spruce— Picea  canadensis.  Wt  24  lb  Fiber  ?  S  m 
Range — Newfoundland  to  Hudson  Rpv  ^  ° 

to  Northern  New  York.  Michigan  feonsfn " M  Alaska;  southward 

and  British  Columbia.  ^  Minnesota,  South  Dakota,  Montana 

Common  Names — White  Snnmp  (\T^  m  tr  , 

P"/.  ):  Single  Spruce  (Me.^  Vt.  AHnn  V '  W-f’’  m  ^ich.,  Minn., 

(Wis.,  Me  New  Eng.,  Ont.);  CaT  Spruce^fMe^^  Net ‘'f  Spruce 

(Hudson  Bay) ;  Double  Spruce  (Vt  )^  ^  Eng.);  Spruce  (Vt.);  Pine 

Sulphite  Pulp 

Yield  1,030  lb.  Easily  bleached. 

stren^h— excellent  color. 

and  is  used  for  news,*^wrappi‘ng‘^°boik^*^hiB-h*'®  standard^  sulphite  pulpwood 
Sulphate  Pulp  book,  high-grade  printings,  etc. 

Yield  1,150  lb. 

Character-— Very  strong  fine  fiber. 

Mechanical  PuTp'~^^^^^^^  ^nd  strong  fiber  board. 

Yield  2,400  lb. 

color,  and  strength. 

required.  P''^‘=‘‘oally  every  purpose  where  groundwood  pulp  is 

Alpine  Fir— Abie  lasiocarpa.  Wt.  21  lb.  Fiber  _ 

westward  through°'^notthern^’oregon”’  and’^°’^^‘^tl  Montana  and  Idaho,  and 
degrees).  ^  nortnern  Oregon  and  northward  to  Alaska  (latitude  60 

'  Slf  ifolo.,  Utah.  Idaho,  Oreg.); 

tree  Alpine  Fir;  Mtuntam  Ssam  Balsam-tree  (Cal.);  Pumplit 

Sulphil^Pulp’  Sub-Alpine  Fk  (Car^lit.)  =  Downcone 

Yield  1,010  lb.  Easily  bleached. 

Pn^llhi  Pu'Pcd— good  strength— excellent  color 
SulphatTpulp  ^  substitute  for  white  spruce. 

Yield  1,050  lb. 

^  fiber.  Excellent  strength. 

Yield  2,070  lb. 

strength. 

AiwiPaTTc  — Same  as  white  spruce. 

Amabalis  Fir— Abie  amabalis.  M't.  22  lb.  Fiber  _ 

mountains)°To  W^sWngton'^^'d'^O^fg’^r'^  southward  in  the  Cascade 

Lore^°  Fi/^(Caf~lh^)'^  Lore!  ^*R  rP  (Western  Mountains);  Fir  (Cal)- 

Sulphite  Pulp 

Yiejd  1,060  lb.  Easily  bleached 

pulped— fair  strength— excellent  color.. 

SulphTe  %p'‘''~^^  ^  substitute  for  white  spruce. 

Yield  1,100  lb. 

Character— Long  fiber,  excellent  strength. 

Mechanfcal"pZ7 

Yield  1,870  lb. 

Character— Long  fiber  of  excellent  strength;  color  slightly  gravish 
Possible  Uses—Same  as  white  spruce.  siigntiy  grayish. 

B.alsam  Fir— Abie  balsamea.  Wt.  21  lb.  Fiber  27mm 

GrraTBfa^lakrremSS^^aJd^souJf^^^^^  Hudson  Bay  and  northwestward  to 

to  Virginia),  Michigan  and  Minnesota  ^  "^yl'^ania  (and  along  high  mountains 

“Blisters”  (NV  Y.  I^diai^^)  (Hudson  Bay)  Sapin  (Quebec);  Cho-koh-tung=r 
Sulphite  Pulp 

Yield  970  lb.  Easily  bleached. 

^  strength— excellent  color.  , 

Sulphate  Pulp"""~^^  ^  substitute  for  white  spruce. 

Yield  1,010  lb. 

Character—  High  grade  kraft  fiber. 

Possible  Uses — Same  as  white  spruce. 


576  MODERN  PULP  AND  PAPER  MIAKING 

Mechanical  Pulp 
Yield  1. 910  lb. 

Character — Good  fiber  length,  strong  and  good  color. 

Possible  Uses — Same  as  white  spruce. 

Grand  Fir — Abies.  Grandis  Wt.  23  lb  Fiber  3.2  m.  m. 

Range — Coast  region  trom  V'ancouver  Island  to  California  (Mendocino  County), 
and  from  Washington  and  Oregon  to  Northern  Idaho  and  Montana. 

Common  Names — White  Fir  (Cal.,  Oreg.,  Idaho);  Silver  Fir  (Mont.,  Idaho); 
Yellow  Fir  (Mont.,  Idaho);  Oregon  White  Fir  (()al.);  Western  White  Fir; 
Grand  or  Oregon  VVhite  Fir  (Cal.  lit.);  Great  California  Fir  (lit.). 

Sulphite  Pulp 

Yield  890  lb.  Easily  bleached. 

Easily  pulped — fair  strength — excellent  color. 

•  Possible  Uses — ^As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,140  lb. 

Character — Good  strong  grade  of  kraft  pulp. 

Possible  Uses — Same  as  white  spruce. 

Mechanical  Pulp 
Yield  1,950  lb. 

Character — Good  fiber,  color  and  strength. 

Possible  Uses — Same  as  white  spruce. 

Noble  Fir — Abies  nobilis.  Wt.  22  lb.  Fiber  - . 

Range- — Washington  (coast  mountains  in  southwestern  part  of  state;  Olympic 
Mountains  on  Solduc  river;  from  Mount  Baker  southward  in  the  Cascade 
Mountains)  to  Oregon  (Browder  Ridge  on  headwaters  of  McKinzie  river  in  Lane 
County).  Range  at  present  but  little  known. 

Common  Names — Red  Fir  (Oreg.);  “Larch”  (Oreg.  lumbermen);  Noble  Fir 
(Oreg.);  Big  tree;  Feather  Red  Fir  (Cal.  lit.);  Noble  or  Brocted  Red  Fir 
(Cal.  lit.);  Tuck  Tuck  (Pacific  Indians). 

Sulphite  Pulp 

Yield  1,010  lb.  Easily  bleached. 

Easily  pulped — poor  strength — excellent  color. 

Possible  Uses~As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,080  lb. 

Character' — Good  quality  of  strong  pulp. 

Possible  Uses — Same  as  white  spruce. 

Mechanical  Pulp 
Yield  1,920  lb. 

Character — Very  long  strong  fiber — good  color." 

Possible  Uses — Same  as  white  sprue  e. 

Red  Fir — Abies  magnifica.  Wt.  23  lb.  Fiber  - . 

Range — Southern  Oregon  (Cascade  Mts.)  and  California  (Mount  Shasta  and 
along  the  western  slope  of  Sierra  Nevada  Mountains). 

Common  Names — Red  Fir  (Cal.).;  California  Red-bark  Fir  (Cal.);  Magnificent 
Fir  (Cal.  lit.);  California  Red  Fir  (Cal.  lit.);  Golden  Fir  (Cal.  lit.). 

Sulphite  Pulp 

Yield  1,080  lb.  A  little  hard  to  bleach. 

Easily  pulped — good  strength — fair  color. 

Possible  Uses — As  a  substitute  for  white  spruce.  _ 

Sulphate  Pulp 

Yield  1,150  lb. 

Character — Good  strong  fiber. 

Pospble  Uses — Same  as  white  spruce. 

Mechanical  Pulp 
Yield  1,915  lb. 

Character^ — Pinkish  color — fair  strength. 

Possible  Uses — As  a  substitute  for  white  spruce. 

White  Fir — Abies  Concolor.  Wt.  22  lb.  Fiber  3.5  m.  m. 

Range — Oregon  (Siskiyou  Mountains)  to  Southern  California  (San  Bernardino 
County);  Northern  Arizona  and  New  Mexico  to  Colorado  and  Utah  CW  asatch 
Mountains). 

Common  Names — White  Fir  (Cal.,  Idaho.  Utah.  Colo.);  Balsam  Fir  (Cal., 
Idaho,  Colo.);  Silver  Fir  (Cal.);  Balsam  (Cal.);  White  Balsam  (Utah);  Bastard 
Pine  (Utah) ;  Balsam-tree  (Idaho) ;  Black  Gum  (Utah) ;  California  White  Fir 
(Cal.);  Colorado  White  Fir  (Cal.  lit.);  (Concolor  Silver  Fir  (Eng.  lit.). 

Sulphite  Pulp 

Yield  950  lb.  Easily  bleached. 

Easily  pulped — good  strength — good  color. 

Possible  Uses — As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,100  lb.  . 

Character — Good  strong  grade  of  kraft  pulp. 

Possible  Uses — Same  as  white  spruce. 

Mechanical  Pulp 

Yield  2,010  lb.  Satisfactory  color — fair  strength — good  fiber. 

Possible  Uses — As  a  substitute  for  white  spruce. 

Douglas  Fir — Pseudotsuga  laxifolia. 

Washington  and  Oregon.  Wt.  28  lb.  Fiber  and  4.4.  m.  m. 

Montana  and  Wyoming — Wt.  25  lb.  Fiber  - . 


AMERICAN  PULPIVOODS 


S77 


feXrBdt“l/colS°S; 

iruce”(c^rcoi^?^AoS:)/g^o:fgias^^^^^^ 

Mont  Idaho,  Wash.);  Spruce  (Xnt.)T  hlr  (kgr)^-’ 

Cork:blrked  D^uglif  Spr Douglas-tree; 
Sulphite  Pulp 

'•’  •«  -"">■  f--  -renph-poo,  color. 

Sulphate  Pulp 

Yield  1,170  lb. 

'  .grade  of  kraft  pulp  but  not  as  strong  as  white  spruce 

Possible  Uses — Similar  to  white  spruce  wuuc  spruce. 

Hemlock— Tsuga  canadensis.  Wt.  24  lb.  Fiber  30mm 

i?ange— Nova  Scotia  to  Minnesota  (Carleton  County),’  Wisconsin  Michigan  and 

“iJlirn-  Z^TeoiT"  ■'“*  n"«"™ 

gmmon  Nmim.-Hemlock  (Me  N.  H  Vt  Mass..  R.  I.,  Conn.,  N.  Y.,  N  J 

Spruce ^-Vtl'-R.^L,  n’.  Y..^Pa.^^N  f  V^”  N ‘c  ”  S°'r°’  ^  Hemlock 

Spruce  (Pa.,  W.  Va.);  Spruce  Pine  (Pa^’ Del  Va  C  Ca^'^^Ol"  ’  ’ 

H^XkTlit.)?  Hemlock•VIS^N°w"lm^lt1 

Sulphite  Pulp 

Yield  1,080  lb.  A  little  hard  to  bleach. 

Not  .epily  pulped.  Good  strength — fair  color 

SulfC‘  pilP  ‘ 

Yield  2,030  lb.  1 

Character — Good  strong  pulp. 

Possible  Uses — Similar  to  white  spruce 
Mechanical  Pulp 
Yield  2,030  lb. 

Character — Pinkish  color — short  fiber. 

Possible  Uses  As  a  substitute  for  white  spruce 
Western  Hemlock — Tsuga  heterophylla.  Wt.  23  lb.  Fiber  27mm 

r.rgS7fociif'o°r, ?r„Ty)  ““  «"  'h'  Cisc.dc  and  coast 

te!%d"ahr7?,r)'r'‘w?s'’,s?  iSa^cSc™ 

Spruce;  Western  Hemlock  Fir  (Eng.);  Prince  Albert’^  F^r  rFnJr^i  Hemlock 
Pine  (Northwestern  lumbermen).  Alberts  Fir  (Eng.);  Alaska 

Sulphite  Pulp  • 

Yield  1.050  lb.  Easily  bleached. 

Easily  pulped — good  strength — fair  color. 

Possible  Uses — Same  as  white  spruce. 

Sulphate  Pulp 

Yield  1,100  lb. 

Character — Good  strong  fiber. 

Possible  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 
Yield  2,160  lb. 

•  Character— Good  strength  and  fiber— grayish  color. 

Fossible  Uses — Similar  to  white  spruce. 

Tamarack — Larix  laricina.  Wt.  31  lb.  Fiber  2.6  mm 

Range— From  Ne\v  Foundland  and  Labrador  to’ Northern  Pennsylvania  Northern 
Indiana  Illinois,  Central  Minnesota,  and  northwestward  to  Hudson  Bay  (Cape 
Churchill,  Great  Bear  Lake,  and  Mackenzie  River)  (in  Arctic  Circle)  ^ 

Comwiow  Namw— Larch  (Vt.,  Mass.,  R.  L,  Conn..  N.  Y.  N.  J  Pa  Del  Wis 
Minn.  Ohio,  Ont.);  Tamarack,  (Me.,  N  H.,  Vt..  Mass.,  R.  I  ”  N  ’y  n’ 

Mass^”R^”l  ”  Dei’  ’  Hackmatack  (Me.  H.’  H. 

Mass.,  i-j  Minn.,  Ont.);  American  Larch  (Vt.,  Wis  nurservmenV 

mS;  Hacticl: 

Sulphite  Pulp 

Yield  1,270  lb.  Difficult  to  bleach. 

Difficult  to  pulp — good  strength — poor  color. 
l^osstble  uses — Low  grade  wrappings. 

Sulphate  Pulp 

Yield  1,400  lb. 

Character — strong,  tough  pulp. 

Possible  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 
Yield  2,620  lb. 

Character — Short  fibered  and  gray  color, 
ur  Possible  Uses — As  a  substitute  for  white  spruce 
Western  Larch— Larix  occidentals.  Wt.  28  lb.  Fiber  2.6  m.  m 

pSo^thern  British  Columbia  (south  of  latitude  S3  degrees)  and  south 
in  the  Cascade  Mountains  to  the  Columbia  River  and  to  Western  Montana;  also 


5/8  ?^IODERN  PULP  AND  PAPER  MAKJNU 

\ 

in  Jilue  Movmtains  of  Washington  and  Oregon. 

Common  Names — Tamarack  (Oreg.):  Hackmatack;  r..arch  (Idaho,  Wash.,  etc.); 

Red  American  Larch;  Western  Hamarack;  Western  Larch  (Eng.);  Great 
Western  Larch  (Cal.  lit.). 

Sulphite  Pulp  • 

Yield  1,200  lb.  Difficult  to  bleach.  Difficult  to  pulp — poor  strength  and 
color. 

Possible  Uses — Low  grade  wrappings. 

Sulphate  Pulp 

Yield  1,290  lb. 

Character — Good  quality  of  kraft  fiber. 

Possible  Uses — Same  as  white  spruce. 

Mechanical  Pulp 
Yield  2,100  lb. 

Character — Brown  color,  short  fiber  and  fair  strength. 

Possible  Uses — Where  a  medium  quality  of  ground-wood  will  answer  the 
purpose. 

Jack  Pine — Pinus  divaricata.  Wt.  24  lb.  Fiber  2.5  m.  m.  , 

Range — New  Brunswick  to  New  Hampshire  and  west  through  Great  Lake 
and  Hudson  Bay  (southern  shores)  region  to  Great  Bear  Lake,  Mackenzie  river, 
and  Rocky  Mountains;  south  into  Northern  Maine,  Northern  New  York,  Northern 
Indiana  and  Illinois,  and  Central  Minnesota.  _ 

Common  Nantes — Scrub  Pine  (Me.,  Vt.,  N.  Y.,  Wis.,  Mich.,  Minn.,  Ont.);  Gray 
Pine  (Vt.,  Minn.,  Out.);  Jack  Pine  (Mich..  Minn.  Canada);  Prince  Pine  (Ont.); 

Black  Jack  Pine  (Wis);  Black  Pine  (Minn.);  Cypress  (Quebec  to  Hudson  Bay); 

Canada  Horn-cone  Pine  (Cal.  lit);  Cbek  Pine;  Sir  Joseph  Bank’s  Pine  (Eng.); 

“Juniper”  (Canada);  Banksian  Pine  (lit.). 

Sulphite  Pulp 

Yield  1,080  lb.  Very  difficult  to  bleach. 

Not  easily  pulped — fair  strength — poor  color. 

Pulp  shivey  and  full  of  pitch. 

Possible  Uses — Mechanical  difficulties  when  running  this  pulp  over  the  paper 
machine  prevent  its  use. 

Sulphate  Pulp 

Yield  1,150  lb. 

Character — Very  strong,  tough  fiber. 

Possible  Uses — ^Similar  to  white  spruce. 

Meehanical  Pulp 

Yield  2,130  lb.  .  •  v 

Character — Gray,  somewhat  soft,  good  strength,  pitchy,  poor  finish. 

Possible  Uses — Medium  grades  of  ground  wood. 

Loblolly  Pine — Pinus  Tseda.  Wt.  30  lb.  Fiber  3.0  m.  m. 

Range — South  Atlantic  and  Gulf  States  from  New  Jersey  (Cape  May),  Southern 
Delaware  and  West  Virginia  (Wood,  Mineral,  Hampshire,  and  Hardy  counties) 
to  Central  Florida  (Cape  Malabar  and  Tampa  Bay)  and  west  to  Eastern 
Texas  (Colorado  River;  in  Bastrop  County);  northward  into  Southeastern  Indian 
Territory,  Arkansas,  and  southern  border  of  middle  and  West  Tennessee.  _ 

Common  Names — Loblolly  Pine  (Del.,  Va.,  N.  C.,  S.  C.,  Ga.,  Ala.,  I  la..  Miss., 

La.,  Tex.,  Ark.);  Oldfield  Pine  (Del.,  Va.,  N.  C.,  S.  C.,  G.,  Ala.,  Fla.,  Miss., 

La.,  Tex.,  Ark.);  Torch  Pine  (Frog,  lit.);  Rosemary  Pine  (Va.,  N.  C.,  in  part); 

Slash  Pine  (Va.,  N.  C.  in  part);  Longscliat  Pine  (Del.);  Longshucks  (Md.,  VaQ; 

Black  Slash  Pine  (S.  C.) ;  Frankincense  Pine  (lit.);  Short-leaf  Pine  (Va.,  N.  C., 

S.  C.,  La.);  Bull  Pine  (Texas  and  Gulf  region);  Virginia  Pine;  Sap  Pine  (Va.,  N. 

C.) ;  Meadow  Pine  (Fla.);  Cornstalk  Pine  (Va.);  Black  Pine  (Va.);  Foxtail 
Pine  (Va.,  Md.);  Indian  Pine  (Va.,  N.  C.) ;  Spruce  Pine  (Va.,  in  part); 

Bastard  Pine  (Va.,  N.  C.);  Yellow  Pine  North  Ala.,  N.  C.);  Swamp  Pine  (Va., 

N.  C.);  Longstraw  Pine  (Va.,  N.  C.,  in  part). 

Sulphite  Pulp 

Yield  1,140  lb.  Difficult  to  bleach. 

Easily  pulped — good  strength  and  color. 

Possible  Uses- — ^As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,420  lb. 

Character — Strong  but  coarse  fiber. 

Possible  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 
Yield  2,450  lb. 

Character^ — Short  fiber  and  very  pitchy. 

Possible  Uses — C)nly  when  mixed  with  better  grades  of  ground-wood  fibers. 

Lodgepole  Pine — Pinus  murrayana.  Wt  24  lb.  Fiber  2,3  m.  m. 

Range — From  Alaska  (Yukon  river)  and  southward  through  interior  British 
Columbia;  the  mountains  of  Washington  and  Oregon  to  California  (Sierra  '« 

Nevada  Mountains  to  San  Jacinto  Mountains) ;  plateau  east  of  the  Rocky  Moun¬ 
tains  (latitude  56)  and  south  through  the  Rocky  Mountain  region  to  New  Mexico 
and  Northern  Arizona.  Also  Coast  region  from  Alaska  to  California  (Mendocino 
County). 

Common  Names — Tamarack  (Wyo.,  Utah.,  Mont.,  Cal.);  Prickly  Pine  (Utah); 

White  Pirie  (Mont.);  Black  Pine  (Wyo.);  Lodgepole  Pine  (Wyo.,  Mont..  Idaho); 

Spruce  Pine  (Colo.,  Idaho,  Mont.);  Tamarack  Pine  (Cal.);  Murray  Pine  (Cal. 
lit.);  Scrub  Pine;  Knotty  Sand  Pine  (Oreg.);  Bolander’s  Pine;  Henderson’s  Pine; 

North  Coast  Scrub  Pine  (Cal.  lit.). 


AMERICAN  PULPIVOODS 


579 


A  little  hard  to  1  leach. 
Exccdlent  strength  and  color, 
a  substitute  for  white  spruce. 

-Same  as  white  spruce. 


Sulphite  Pulp 

Vield  1, 080  Ib. 

Easily  pulped. 

Possible  Uses — As 
Sulphate  Pulp 

Yield  1,120  lb. 

Character  and  Uses- 
Mechanical  Pulp 
Yield  2,140  lb. 

C/!arac^r  a«d  {/je^— A  little  nitchy  but  otherwise  similar  to  white  spruce. 
Note— The  Lodgepole  pine  which  grows  in  the  lowlands  in  the  coastal  region 

pine  The  Rocky  Mountain  region  lodgepole  pine  how- 
pulp’s.  ™  preferred  for  sulphite  and  mechanical 

Longleaf  Pine— Pinus  Palustris.  Wt.  34  lb.  Fiber  3.7  m.m. 

/fuiigc— Coast  region,  froni  Southern  Virginia  (Norfolk)  to  Florida  (Tampa  Bay 
to  ^  Eastern  Texas  (Trinity  River);  northward  in  Alabama 

western  (borrdt"'coumLf  (^L%g!^^  ^orth- 

Common  Names— Longleaved  Pine  (Va.,  N  C  S  C  Ga  Ala  Fla 

S^C^AI^  Ala..’ Miss.r’L.);  Y’ellow’ Pine ’(£,’  K ‘c": 

b.  C.,  Ala.,  ria.,  La.,  Tex.);  Turpertine  Pine  (N.  C.);  Rosemary  Pine  (N  C ')  • 
Brown  Pine  (Tenn);  Hard  Pine  (Ala,  Miss..  La.);  Georgia  Pine  ^(general  r)H)’ 
Fat  Pine  (Southern  State^ ;  Southern  Yellow  Pine  (general);  Southern  Hard 
Heart^pInr^N  Southern  Heart  Pine . (general) ;  Southern  Pitch  Pine  (general); 
T  ou^W  H  v^ii  Atlartic  region);  Pitch  Pine  (Atlantic  region); 

No^fh Longstraw  Pine  (Atlantic  region); 

^  Georgia  Yellow  Pine  (Atlantic  region); 
Georgia  Longleaved  Pine  (Atlantic  region); 
Georgia  Pitch  Pine  (Atlantic  region);  Florida  Yellow  Pine  (Atlantic  Region) 
Texas  Longleaved  Pine  (Atlantic  region). 

Sulphite  Pulp 

Yield  1,840  lb.  (crude  pulp).  Cannot  be  bleached 

Very  poor  color.  In  general,  this  wood  cannot  be  considered  satisfactory 
tor  sulphite  pulp. 

Possible  Uses — Few. 

Sulphate  Pulp 

Yield  1,600  lb. 

Character — Strong  but  coarse  fiber. 

Possible  Uses — Similar  to  white  spruce. 

Norway  Pine — Pinus  resinosa.  Wt.  27  lb.  Fiber  3.7  m.  m. 

RoMgc-— From  Newfoundland  and  along  the  northern  shores  of  St.  Lawrence 
Gulf  to  Northern  (Ontario  (north  of  Abitibi  Lake)  to  Southern  Manitoba  (near 
southern  end  of  Lake  Winnipeg) ;  southward  through  the  Northern  States 
to  Mass^husetts  (Middlesex  County),  Pennsylvania  (Chester  County)  North- 

Cleveland),  Central  Michigan  (Saginaw),  Northern  Wis- 
Mnsin  (Oshkosh  and  Eau  Claire)  and  Northeastern  Minnesota 
Common  i\^mw--Red  Pine  (Vt.,  N  H.,  N.  Y.,  Wis..  Minn.,  Ont.)  ;  Norway  Pine 

ffnadia^n  Red  Sne  (Eng.)^’  ^•’  ^^is.); 

Sulphate  Pulp 

Yield  1,330  lb. 

Character  and  Possible  Uses — Similar  to  white  spruce 

Pitch  Pine — Pinus  rigida.  Wt.  29  lb.  Fiber _ . 

Range  From  Southern  New  Brunswick  (St.  Johns  river)  to  Eastern  Ontario 
(north  shore^  ot  Lake  Ontario  and  lower  Ottawa  River)  and  southward  in  the 
Atlantic  region  to  Southern  Virginia  (Norfolk)  and  along  the  mountains  to 
Northern  Georgia  (Atlanta);  west  to  \Vestern  New  York  (Ithaca);  Northeastern 
Pennsylvania,  Eastern  Ohio  (border  counties  south  of  Canton)  and  Kentucky, 
Eastern  Tennessee  (to  Cumberland  Mountains) 

Common  .Vamw— Pitch  :^ne  (Vt  N.  H.,  Mass.  R.  I.,  Conn.,  N.  Y..  N.  J.,  Pa., 
Del.,  W.  Va.,  N.  C.,  S.  C.,  Ga^  Ohio,  Ont.,  Md.,  Eng.)  ;Longleaved  Pine  (Del.)'; 
Lon g=chat  Pine  vDel.);  Black  Norway  ^ne  (N.  Y.)  Hard  Pine  (Mass.);  Yellow 
Pine  (Pa.);  Black  Pine  (N.  C.);  Rigid  Pine  (Eng.  lit.);  Sap  Pine  (lit.). 

Sulphate  Pulp  >  r  / 

Yield  1,430  lb. 

Character  and  Uses — Similar  to  white  spruce. 

Sand  Pine — Pinus  clausa.  Wt.  29  lb.  Fiber  - . 

Range— Coast  of  Alabama  (Baldwin  County)  and  Western  Florida  (to  Pease 
Creek)  east  coast  of  Florida  from  St.  Augustine  to  Halifax  River 
Common  Names— Sar^  Pine  (Fla.,  Ala.);  Oldfield  Pine  (Fla.);  Florida  Spruce 
Pine  ((Ala.);  Scrub  Pine  (Fla.);  Spruce  Pine  (Fla.);  Upland  Spruce  Pine  (Fla.). 
Sulphite  Pulp 

Yield  1,300  lb.  Difficult  to  bleach,  and  shivey. 

Easily  pulped — fair  strength — good  color. 

Possible  Uses — As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,220  lb. 

Character  and  Uses — Similar  to  white  spruce. 

Scrub  Pine — Pinus  virginiana.  Wt.  26  lb.  Fiber  2.8  m.m. 

Range  From  New  York  (Staten  Island)  to  South  (Carolina  (Aiken  River)  and 


58o  modern  pule  AND  PAPER  MAKLNG 

Northern  Alabama  (Winston,  Cullman,  and  Dekalb  counties) ;  west  into  Southern 
Indiana,  to  middle  Tennessee  (Putnam  County). 

Common  Names — Jersey  Pine  (N.  J.,  Pa.,  Del.,  N.  C.,  S.  C.)  ;  Scrub  Pine  (R.  I., 
N.  Y.,  Pa.,  Del.,  N.  C.,  S.  C.,  Ohio);  Short  Shucks  (Md.,  Va.);  Shortshat  Pine 
(Del.);  Spruce  Pine  (N.  J.,  N.  C.) ;  Shortleaved  (N.  C.);  Cedar  Pine  (N.  C.); 
River  Pine  (N.  C.);  Nigger  Pine  (Tenn.) ;  New  Jersey  Pine  (lit.). 

Sulphite  Pulp 

Yield  1,000  lb. 

Difficult  to  bleach,  easily  pulped  and  good  color. 

__  Possible  Uses — As  a  substitute  for  white  spruce. 

Sulphate  Pulp 

Yield  1,250  lb. 

Character — Strong  but  coarse  fiber. 

Possible  Uses — Similar  to  white  spruce. 

Sugar  Pine — Pinus  lambertiana.  Wt.  23  Ib.  Fiber  4.1  m.m. 

Range — Coast  region  from  Oregon  (head  of  Mackenzie  and  Rogue  rivers)  to 
California  (Sierra  Nevada  Mountains  and  coast  ranges  to  Santa  Lucia 
Mountains;  San  Bernardino  and  Cuyamac  Mountains). 

Common  Names — Sugar  Pine  (Cal.,  Oreg.);  Big  Pine;  Shade  Pine  (Cal.);  Great 
Sugar  Pine;  Little  Sugar  Pine;  Gigantic  Pine  (Cal.  lit.);  Purple-coned  Sugar 
Pine. 

Sulphite  Pulp 

Yield  1,010  lb.  A  little  difficult  to  bleach. 

Easily  pulped.  Poor  strength— fair  color. 

Possible  Uses — Dark  colored  wrappings. 

Sulphate  Pulp 

Yield  1,150  lb. 

Character  and  Uses — Similar  to  white  spruce. 

Western  Yellow  Pine — Pinas  ponderosa.  Wt.  24  lb.  Fiber  3.6  m.m. 

Range — From  British  Columbia  (interior  south  of  latitude  51°),  and  Dakota 
(Black  Hills  region),  southward  in  the  Pacific  and  Rocky  Mountain  region  to 
Western  Texas  and  Mexico. 

Common  Names — Yellow  Pine  (Cal.,  Colo.,  Mont.,  Idaho,  Utah,  Wash.,  Oreg.); 
Bull  Pine  (Cal.,  Wash.,  Utah,  Idaho,  Oreg.);  Big  Pine  (Mont.);  Longleaved 
Pine  (Utah,  Nev.);  Red  Pine;  Pitch  Pine;  Southern  Yellow  Pine;  Heavy-wooded 
Pine  (Eng.);  Western  Pitch  Pine;  Heavy  Pine  (Cal.);  Foothills  Yellow  Pine; 
Sierra  Brownbark  Pine;  Montana  Black  Pine  (Cal.  lit.);  “Gambier  Parry’s  Pine” 
(Eng.  lit.). 

Sulphite  Pulp 

Yield  1,130  lb.  Difficult  to  bleach,  shivey. 

Not  difficult  to  pulp.  Very  poor  strength  and  color. 

Possible  Uses — Few. 

Sulphate  Pulp 

Yield  1,100  lb. 

Character^ — Fine,  high  grade,  very  strong,  and  tough  fiber. 

Possible  Uses — Same  as  white  spruce. 

Mechanical  Pulp 
Yield  2,060  lb. 

Character — Fibers  are  long,  coarse  and  soft,  creamy  color  and  somewhat 
pitchy. 

Possible  Uses — Where  a  medium  quality  of  ground  wood  will  answer  the 
purpose. 

White  Pine — Pinus  strobus.  Wt.  22  lb.  Fiber  3.8  m.m. 

Range — From  Newfoundland  (White  Bay  region)  and  along  the  northern 
shores  of  St.  Lawrence  Gulf  to  Northern  Ontario  (near  Abitibi  and  Nipigon  lakes). 
Southern  Manitoba  (near  southern  end  of  Lake  Winnipeg);  southward  through 
Northern  and  Eastern  Minnesota,  northeastern  (Mitchell  county)  and  eastern 
border  of  Iowa  (to  Scott  County),  Northern  (counties)  Illinois,  southern 
shores  of  Lake  Michigan,  Southern  Michigan  (north  of  Allegan,  Eaton,  and 
St.  Clair  counties).  Northeastern  and  Eastern  (border  counties)  Ohio,  and  along 
the  Allegheny  Mountains  to  Northern  Georgia,  Tallulah  Falls). 

Common  Names — White  Pine  (Me.,  N.  H.,  Vt.,  Mass.,  R.  I.,  Conn.,  N.  Y.,  N.  J., 
Pa.,  Del.,  Va..  W.  Va.,  N.  C.,  Ga.,  Ind.,  Ill.,  Wis.,  Mich.,  Minn.,  Ohio, 
Ont.,  Nebr.);  Weymouth  Pine  (Mass.,  S.  C.);  Soft  Pine  (Pa.);  Northern  Pine 
(S.  C.);  Spruce  Pine  (Tenn.). 

Sulphite  Pulp 

Yield  1,210  lb.  Difficult  to  bleach. 

Difficult  to  pulp.  Fair  strength,  but  shivey  and  poor  color. 

Possible  Uses — Few. 

Sulphate  Pulp 

Yield  1,100  lb. 

Character — ^Excellent  strength  and  color. 

Possible  Uses — Similar  to  white  spruce. 

Mechanical  Pulp 

Character — Good  strength  and  color,  but  pitchy. 

Possible  Uses — Similar  to  white  spruce. 

Incense  Cedar — Libocedrus  decurrens.  Wt.  23  lb.  Fiber  2  m.m. 

Range — From  Oregon  (North  Fork  of  Sanitam  River  and  southward  on  the 
Western  .slopes  of  the  Cascade  Mountains  through  California  (Western  slopes  of 
Sierra  Nevada  Mountains  and  coast  ranges  from  southern  border  of  Mendocino 


AMERICAN  PULPWOODS 


5S1 

Nevada  ;*Lower  Ca^Hfomk  "(Mo^nt  SanTe’drT  Mountains);  Western 

CedaT7cal%"^;^y/”‘p"osPaar^^^^^  (Cal..  Oreg.);  Incense 

I*’-  Difficult  to  bleach. 

Good  strength— poor  color. 

■I  ossthlc  Few 

Sulphate  Pulp 

Yield  9SO  lb. 

PossMe’'nl?N\  and  hard  fiber. 

region)  t9"‘^!<>ri'S''tMoSSitoYa]J^^ntcIt°Romaro)  “  !'•'  ooasl 

em  and  Northwestern  Kentucky  SoutlSn  XnAi  ^°''‘^/astern  Missouri,  West- 
(Knox  County).  ^  utliern  Illinois,  and  Southwestern  Indiana 

Common  Names — Bald  Cvnress  fDpl  ivr  o  ^ 

Dl->  Ind.);  White  Cypress  (N  C  S  c  ’  vi  Tex.,  Ark., 

Cyp^ess^feef^'^N.’  C  '  ’Swamp  C^y^p'rlls  ^(LaS’’ 

Cypress  (Al^) ;  Deciduous  Cypress 

difficult  to  bleach, 

pS;i  uV^'n!;°"  “<* 

Sulphate  Pulp 

Yield  1,350  lb. 

Tiber  long  but  tender. 

REDwooD-jeluioia  s^^rvireL.®“wt  “3"  lb.°"  ’ 

Jlef  from°moufh,  and  ^oTwKuck  °Riv?rT®a°nd 

(twenty  to  thirty  miles  inland!  thrmiCTh  southward  in  the  coast  region 

pvelve  miles  soufh  of  Salmon  Creek  Canfon, 

0  o^fifiioft  Mayues — Sf'k’iima  (C'n}  \  •  a.  r*  county j, 

Am.  Ht.) ;  California  Redwood  (Eng^  lit  )  ^Cal.);  Redwood  (Cal.  and 

Sulphite  Pulp  * 

Yield  920  lb  Difficult  to  bleach. 

st'-ength— dark  colored. 

SulpZte  %p  wrappings. 

Yield  950  lb. 

Character— Long  fibered  but  tender. 

W„.„  “^yi-Vp  Whi^  ,p™o.  ^ 

to  OmariS°'a"nd  NSfth^Ko,","''  Ea,™/r'N  (“'‘k  ‘°V “"<*  "’'■l»ar<l 
and  Texas  (Trinity  River)  Eastern  Nebraska,  Kansas,  Indian  Territory, 

N  R,  Vk  Map  R  r..  Co„„.,  N.  Y.,  N,  J., 

TfJ'./Ooolioc);  Cane  Ash  (Ala,  Mi^./'L?)  ’’’  dowa);  Franc- 

Sulphite  Pulp 

Yiejd  1,530  lb.  A  little  hard  to  bleach. 

Easily  pulped.  Very  weak.  Poor  color. 

Possible  Uses — Few. 

Soda  Pulp 

Yield  1,350  lb. 

SFwe"F7,t3rew!"'"“  “ 

^3  lb.  Fiber  i  m.m. 

iremoie  tyuePec),  1  rembling  Aspen  (Iowa);  Aspen  Poplar  (Cal.,  Mont.). 


582 


MODERN  PULP  AND  PAPER  MAKING 


S'llphite  Pulp  ' 

Yield  1,30  lb.  Easily  bleached. 

Easily  pulped — very  weak — excellent  color. 

Possible  Uses — Used  with  longer  fibered  stock  for  better  grade  of  papers. 
Soda  Pulp 

Yield  1,080  lb. 

Character^ — Soft  and  short  fibered — easily  bleached. 

Possible  Uses — When  bleached  and  mixed  with  longer  fibered  bleached 
stock  is  well  adapted  for  book,  envelope,  and  high  grade  printings. 

Mechanical  Pulp 
Yield  2,170  lb. 

Character-Short  fibered,  poor  strength,  good  color,  but  may  have  black 
specks  present. 

Possible  Uses— As  a  filler  when  used  with  longer  fibered  stocks. 
Cottonwood — Populus  deltoides.  Wt.  23  lb.  Fiber  1.3  m.m. 

Range — From  Quebec  (Lower  Maurice  River)  and  Vermont  (Lake  Champlain) 
through  western  New  England  and  New  York,  Pennsylvania  (west  of  Alle¬ 
ghenies),  Maryland,  and  Atlantic  States  to  Western  Florida  and  west  to  the 
Rocky  Mountains  from  Southern  Alberta  to  Northern  New  Mexico. 

Common  Names — Cottonwood  (N.  H.,  Vt.,  Mass.,  R.  I.,  N.  Y.,  N.  j.,  W.  Va., 
N.  C.,  Ala.,  Fla.,  Miss.,  La.,  Tex.,  Cal.,  Ky.,  Mo.,  Ill.,  Wis’.,  Kans..' 
Nebr.,  Iowa,  Minn.,  Mich,  Ohio,  Ont.,  Colo.,  Mont.,  N.  Dak.);  Big  Cotton¬ 
wood  (Miss.,  Neb.);  Yellow  Cottonwood  (Ark.,  Iowa,  Neb.);  (]lotton-tree  (N. 
Y.);  Carolina  Poplar  (Pa.,  Miss.,  La.,  N.  Mex.,  Ind.,  Ohio);  Necklace  Poplar 
Texas,  Colo.);  Vermont  Poplar  (Vt.);  Whitewood  (Iowa);  Broad-leaved  Cotton¬ 
wood  (Colo.). 

Sulphite  Pulp 

Yield  1,035  Easily  bleached. 

Easily  pulped — very  weak.  Excellent  color. 

Possible  Uses — Same  as  aspen. 

Soda  Pulp 

Yield  1,030  lb.  ‘ 

Character — Soft  and  easily  bleached. 

Possible  Uses — Same  as  aspen. 

Mechanical  Pulp 
Yield  2,180  lb. 

Character — short  fibered,  weak,  good  color. 

Possible  Uses — As  a  filler  when  used  with  longer  fibered  stocks. 

Basswood — Tilia  americana.  Wt.  21  lb.  Fiber  i.i  m.m. 

Range — New  Brunswick  to  Virginia  and  (along  Allegheny  Mountains)  to  Georgia 
and  Alabama  (mountains);  west  (in  Canada)  to  Lake  Superior  (eastern  shores) 
and  to  Lake  Winnipeg  (southern  shores)  and  Assiniboine  River  (in  United  States), 
to  Eastern  Dakota,  Eastern  Nebraska,  Kansas,  Oklahoma,  and  Eastern  Texas. 
Common  Names — Basswood  (Me.,  N.  H.,  Vt.,  R.  I.,  Mass..  Conn.,  N.  Y.,  N.  J., 
Del.,  Pa.,  W.  Va.,  D.  C.,  N.  C.,  S.  C.,  Ga.,  Ala.,  Miss.,  La., 

Ark.,  Ky.,  Ill.,  Ind.,  Iowa,  Wis.,  Mich..  Ohio,  Ont.,  Neb.,  Kan..  Minn., 
N.  Dak.);  American  Linden  (Me.,  N.  H.,  R.  I.,  N.  Y.,  Pa.,  Deb,  N.  C.,  Miss., 
Ohio,  Ill.,  Neb.,  N.  Dak.,  Ont.,  Minn.);  Linn  (Pa.,  Va.,  W.  Va.,  Ala.,  La., 

Ill.,  Ind.,  Ohio,  Mo.,  Iowa.  Kans.,  Nebr.,  Wis..  S.  Dak.);  Linden  (Vt.,  R.  I., 

Pa.,  W.  Va.,  Nebr.,  Minn.);  Limetree  (R.  I.,  N.  C.,  S.  C.,  Ala.,  Miss.. 

La.,  Ill.);  Whitewood  (Vt.,  W.  Va.,  Ark.,  Minn..  Ont.);  Beetree  (Vt.,  W.  Va., 
Wis.);  Black  Limetree  (Tenn.) ;  Smooth-leaved  Limetree  (Tenn.);  White  Lind 
(W.  Va.) ;  Wickup  (Mass.);  Yellow  Basswood  (Ind.);  Lein  (Ind.). 

Soda  Pulp 

Yield  1,020  lb. 

Character — Soft  and  easy  bleaching. 

Possible  Uses — Similar  to  aspen. 

Paper  Birch — Betula  papyrifera.  Wt.  34  lb.  Fiber  1.2  m.m. 

Range — From  Labrador  to  Hudson  Bay  (southern  shores).  Great  Bear  Lake. 
Yukon  River  and  coast  of  Alaska;  southward  to  New  York  (Long  Island)  and 
Northern  Pennsylvania,  Central  Michigan,  and  Minnesota.  Northern  Nebraska 
(Bluffs  of  Niobrara  River),  Dakota  (Black  Hills),  Northern  Montana,  and 
Northwestern  Washington  (near  Seattle). 

Common  Names — Paper  Birch  (N.  H.,  Vt..  Mass.,  R.  I.,  Conn.,  N.  Y..  Wis., 
Mich.,  Minn.,  Ont.);  Canoe  Birch  (Me.,,  Vt.,  N.  H.,  R.  I.,  Mass.,  N.  Y..  Pa., 
Wis.,  Minn.,  Ont.) ;  White  Birch  (Me.,  N.  H.,  Vt.,  R.  I.,  N.  Y.,  N.  I., 
Wis.,  Minn.,  Mich.,  Nebr.,  Ont.);  Silver  Birch  (Minn.,  N.  Y.);  Large  White 
Birch  (Vt.) ;  Boleau  (Quebec). 

Sulphite  Pulp 

Yield  1,500  lb.  Difficult  to  bleach. 

Easily  pulped — poor  strength  and  color. 

Possible  Uses — Few. 

Soda  Pulp 

Yield  1,350  lb. 

Character — More  difficult  to  reduce  than  aspen — soft,  easily  bleached. 

Possible  Uses — Similar  to  aspen. 

Mechanical  Pulp 
Yield  3,000  lb. 

Character — Pinkish  color — short  fiber  and  poor  strength. 

Possible  Uses — As  a  filler  with  long  fibered  stocks. 


AMERICAN  PULPIVOODS 


,,  583 

\ELLow  Birch— Betula  lutea.  \Vt  Ih 

Range — From  N-'wfounclIanrI  i-5  m.m. 

^ield  1,590  Ib.  Easily  bleached 

weak— good  color. 

Soda  Pifp"  C/^«-Same  as  aspen. 

Yield  1,360  lb. 

?5S"F“"l.?if3”i'.'s°pen‘'"'  easily  bleached. 

Chestnut— Castanea  dentata.  Wt.  25  jbs  Fib^r  t  „ 

Soufhern  Ontar?o°,“and™So^^^^^^^  ‘^^Northwestm-n^  Vermont  (Winooski  River), 
Mountain^ o  Centra? SSky  and^T^^^^^^^  Indiana  and  on  thf ^AHe^hen y 

Common  Chestnut  (Me.,  N  H  Vt  Ma«  p  Alabama,  and  Mississippi. 

Del.,  Md.,  Va..  W.  Va  N  C  C,P  Ai’,  at-  Conn.,  NY  N  T 

B"”  (Indiana,  n”  A  ’  Ont.);’0-hgt 

sulphite  Pulp 
Not  pulped. 

Soda  Pulp 

Ymld  (on  extracted  chips)  950  lb 

little  hard  to  cook. 

very  difficult  to  reduce  and  ^kaclF  pulped  but  is 

CucuMBER-TRER-Magnolia  acuminata  Wt  27  lb  Fih.r 
Range — From  Western  New  York  thrn„  Jif  c  bi,  ^ 

and  south  in  the  Appalachian  Monnta,S?<^  Ontario  to  Southern  Illinois 

^“'■theastern  Mississippi  (Meridian)-^ 

Nashville  and  eastern  part  of  State)’  Northeast^n  *  Tennessee  (near 

Arkansas.  '  ’  ^  ortneastern.  Southern  and  Southwestern 

Oofnnion  Rames — Cucumber-tree  TR  T  A/r-,..c  at  -n. 

.C-.  Ala.,  Miss.,  La.,  Ark.,  Ky.,  W  Va  Ohio  Tnd  ^Tn  a^'aF'  N-  C., 

Wiss.  ky.);  Cucumber  (\\t.  Va  )•  Black  Hn’  cw’’  v  ‘a’  ^“tintain  Magnola 
Pointed-leaved  Magnolia  (lit)  ’  '  Va.);  Magnolia  (Ark.); 

Soda  Pulp 

Yield  1,200  lb. 

“P«”- 

^^Ic.'j^^Tc’JrMaTnc  “JSnnSc  "Vffori'/.  fV'  ■  ' 

Bay)  and  west  to  Southern  Ontario  Southern  Mfchi^p^^'r™^*  Tampa 

Southeastern  Missouri,  and  Texas  (BrLos  River)  ^  ^  County), 

Common  NamcT— Black  Gum  (N.  J.,  Pa.,  Del.,  W.,  W.  Va  N  C  Sr  r 

N.  J.,  Pa.’,  S!'’vi!‘w^Va’.,^S.'’c^"Fffi.  ^Fex  oT 

Mast  R  I.’,  C^'’tS^'’  mH’ 

Soda  Pulp 

Yield  1,300  lb.  -- 

Mechanical  Pulp 
Yield  2.610  lb. 

Character--Very  short,  but  tough  fiber,  very  white  color 

Cotton  ^ses—As^  filler  with  longer  fibered  stocks. 

COTTON  Gum— Nyssa  aquatica.  Wt.  29  lb.  Fiber  1.6  m  m 

iSlS'sS- sss's:?ss^ 

Sulphite  Pulp 

Yield  1,160  lb.  Easily  bleached 
Ea.sily  pulped.  Poor  strength— fair  color. 

Possible  Uses — ^Same  as  aspen. 

Soda  Pulp 

Yield  1,200  !b. 

.I>P.t  harder  to  bleach  than  aspen. 

Possible  Uses — Similar  to  aspen. 


584  MODERN  PULP  AND  PAPER  MAKING 

£Lg^From^“conneSf  C^nfyf^tp  '^Southeastern  Missouri  _  and 

A?kfLas;  south  to  Florida  (Cape  Canaveral  and  Tampa  Bay)  and  Texas  (Trinity 

cSon ’Ara;n..-Sweet  Gum  (Mass  R.  I.  N.  Y.,  N  J.,  Pa  Del  Va.  W. 
Vr.  ^  C  S  C..  Ga.,  Ala.,  Fla.,  Miss.,  La..  Tex.,  Ark.,  Ky.,  Mo., 
Ill  ’  Ind.  Ohio);  Liquidamber  (R.  I-.  N.  Y.,  Del^  N.  J.,  Pa.,  Tex.,  Ohio, 

Tin-  Red  Gum  (Va.,  .41a.,  Miss.,  Tex.,  La.);  Gum  (Va.);  Gumtree  (S.  C., 
La.);  Alligator-wood  (N.  J.);  Bilsted  (N.  J.) ;  Starleaved  Gum;  Satin  Walnut 

(lumber  markets). 

Sulphite  Pulp  ,  ,,  , 

Yield  1,190  lb.  Difficult  to  bleach. 

Easily  pulped — very  poor  strength — dark  colored. 

Possible  Uses — Few. 

Soda  Pulp 

Yield  i,o8r,  lb.  ...v  ,  j 

Character — .4  little  more  difficult  to  reduce  than  aspen. 

Soft  and  hard  to  bleach. 

Possible  Uses — Same  as  aspen. 

Red  Oak — Quercus  rubra.  Wt.  35  lb.  Fiber  i.S  m.m.  ,  >  j  1 

Eongc— Nova  Scitia  and  Southern  New  Brunswick  through  Quebec  and  along 
the  north  shores  of  Lake  Huron  to  near  Lake  Namekagon;  south  to  Middle  Ten¬ 
nessee  and  Virginia,  and  along  the  Appalachian  Mountains  to  Northern  Georgia; 
west  to  Eastern  Nebraska,  Central  Kansas.  t>  t  xt  v  xt  t  Oo 

Common  Names — Red  Oak  (Me.,  Vt.,  N.  H.,  Mass.  R.  I.,  N.  Y.,  N.  J.,  Pa., 
Del’  Va  W  Va  N.  C.,  S.  C.,  Ga.,  Ark.,  Mo.,  Ky.,  Ill.,  Ind.,  Iowa, 
Nebr  ,  Kans.,  Mich.,  Minn.,  S.  Dak.,  Ont.)  ;  Black  Oak  (Vt.,  Conn.,  N.  Y.,  Wis., 
Iowa,  Nebr.,  S.  Dak.,  Ont.);  Spanish  Oak  (Pa.,  N.  C.), 

Sulphite  Pulp 

Yield  1,600  lb.  Easily  bleached. 

Easily  pulped.  Very  weak — poor  color. 

Possible  Uses — Few. 

Soda  ■  Pulp 

Yield  1,400  lb.  ,  , ,  , 

Character — Very  difficult  to  pulp  and  bleach. 

Possible  Uses — Few. 

White  Oak— Quercus  alba.  Wt.  37  lb.  Fiber  1.5  m.m.  j 

Range — From  Southern  Maine  to  Southwestern  Quebec  and  through  Central 
Southern  Ontario,  lower  peninsula  of  Michigan  and  Southern  Minnesota  to  ^uth- 

eastern  Nebraska  and  Eastern  Kansas;  south  to  Northern  Florida  and  Texas 

Brazos  river).  ,  ,,  ,,  „  ^  xt 

Common  Names — White  Oak  (Me.,  N.  H.,  Vt.,  Mass.,  R.  I.,  Conn.,  N.  Y., 

N.  L,  Pa.,  Del.,  Va.,  W.  Va.,  N.  C.,  S.  C.,  Ala.,  Fla.,  Ga.,  Miss.,  La., 
Tex.,  Ky.,  Mo.,  Ohio,  Ill  ,  Ind.,  Kans.,  Nebr.,  Mich.,  Wis.,  Mmn.,  S.  Dak. 
(cult.),  Iowa,  (Ont.);  Stave  Oak  (Ark.). 

Soda  Pulp 

Yield  1,480  lb. 

Character — Difficult  to  pulp  and  bleach. 

Possible  Uses — Few. 

Sycamore- — Plaxtanus  occidentals.  Wt.  29  lb.  Fiber  1.7  m.m. 

Range — Southeastern  New  Hampshire  and  southern  Maine  to  northern  Vermont 
and  Lake  Ontario  (Don  River,  near  north  shores  of  the  lake);  west  to  eastern 
Nebraska  and  Kansas,  and  south  to  northern  Florida,  central^  Alabama  and 
Mississippi,  and  Texas  (Brazos  river  and  thence  south  to  Devils  river). 

Common  Names — Sycamore  (Vt.,  N.  H.,  Mass.,  Conn.,  R.  I.,  N.  Y.,  N.  J.,  Pa., 
Del.,  Va.,  W.  Va.,  N.  C.,  S.  C.,  Ga..  Fla.,  Ala.,  Miss.,  La.,  Tex., 
Ky.,  Ark.,  Mo.,  Ill.,  Ind.,  Iowa,  Kansas,  Nebr.,  Mich.,  Wis.,  Ohio.  Ont.); 
Buttonwood  (Vt.,  N.  H.,  R.  I.,  Mass.,  N.  Y.,  N.  J.,  Pa.,  Del-v  S.  C.,  Ala., 
Miss.,  La.,  Tex.,  Ark.,  Mo.,  Ill.,  Nebr.,  Mich.,  Minn.,  Ohio,  Ont.);  Button  ball- 
tree  (Mass.,  R.  I.,  Conn.  N.  Y.,  N.  J.,  Pa.,  Del.,  Miss.,  La.,  Mo.,  Ilk, 
Iowa,  Mich.,  Nebr.,  Ohio);  Buttonball  (R.  I.,  N.  Y.,  Pa.,  Fla.);  Planetree 
(R.  I.,  Del.,  S.  C.,  Kans.,  Nebr.,  Iowa);  Water  Beech  (Del.);  Platane  (La.); 
Cotonier  (La.);  Bois  puant  (La.)  Oo-da-te-cha-wun-nes=“Big  stockings”  (In¬ 
dians,  N.  Y.). 

Soda  Pulp  , 

Yield  1,300  lb. 

•  Character — Soft,  easily  bleached. 

Possible  Uses — Similar  to  aspen. 

Black  Willow — Salix  nigra.  Wt.  21  lb.  Fiber  0.8  m.m. 

Range — New  Brunswick  to  southern  Florida  and  west  to  eastern  Dakota,  Nebraska, 
Kansas,  Oklahoma,  southern  Arizona,  and  south  into  Mexico.  In  California 
Sacramento  River  to  Arizona. 

Common  Names — Black  Willow  (N.  H.,  Vt.,  R.  I.,  N.  Y.,  Pa.,  Del.,  S.  C., 
Fla.,  Ala.,  Miss.,  La.,  Tex.,  Ariz.  (Tal.,  N.  Mex.,  Utah,  Ill.,  Wis.,  Mich., 
Minn.,  Nebr.,  Kan.,  Ohio,  Ont.,  N.  Dak.);  Swamp  Willow  (N.  C.,  S.  C.) ; 
Willow  (N.  Y.,  Pa.,  N.  C.,  S.  C.,  Miss.,  Tex.,  Cal.,  Ky.,  Mo.,  Nebr.). 

Sulphite  Pulp 

Yield  1,150  lb.  Easily  bleached. 

Easily  pulped.  Very  weak — excellent  color. 

Possible  Uses — Same  as  aspen. 


AMERICAN  PULPWOODS 


585 


Soda  Pulp 

Yield  g‘50  lb. 

Character— Soft  and  easily  bleached. 
rosstble  Uses — Similar  to  aspen 
Beech— Fagus  atropunicea.  Wt.  36  lb.'  Fiber  _ 

so^tf  to  ,^Is^efn°l?ror[d°a  afd  JesT7^  sSe\sttrSisloli\^^ 

Common  Names — Beech  (Me  N  FT  Vt  r.  t  ^ 

Pa.,  Del..  Va.,  W.  Va.  N  C  S  r  ’  r  N.  Y.,  N.  J.. 

gji 

Soda  Pulp 

Yield  1,530  lb. 

aspen-soft,  easily  bleached. 


AVERAGE  WEIGHTS  OF  SPECIES  OF  WOOD 

bli^'thTn  "f  determinations  given  in  the  following  ta- 

We,  the  U.  S  Forest  Products  Laboratory  used  small,  clear  speci¬ 
mens  seemed  from  the  top  4  feet  of  the  16-foot  butt  logs  of  tvpi- 

thL  t^e  a  trifle  heavier 

nn=?c  %  T  1^  ordinary  ties,  structural  timbers,  poles  and 
posts.  Such  large  pieces  usually  include  the  pith  or  are  taken 

IncouSerer’  ^ 


Weights 


Species  and  Locality 


Kiln-dry  Air-dry  Green 
(i)  (2)  (3) 


DECIDUOUS 

. .Snohomish  Co.,  Wash. . 

<<  ’  ®'hmore . Overton  Co.,  Tenn.  .  .  . 

„  °  . Ostonagon  Co.,  Mich .  . 

,,  ,,  . Marathon  Co.,  Wis _ 

,,  . Bourbon  Co.,  Ky . 

<1  Sreen . Richland  Parish,  La.  .  . 

„  '  . New  Madrid  Co.,  Mo.. 

.<  Oregon . Lane  Co.,  Oregon . 

,,  pumpkin . New  Madrid  Co.,  Mo 

white....... . Stone  Co.,  Ark . ! 

4,  „  . Oswego  Co.,  N.  Y . 

.  . Pocohontas  Co.,  W.  Va 

^spen . Rusk  Co.,  Wis . 

Largetooth . Sauk  Co.,  Wis 

Basswood . Potter  Co.,  Pa .  . ! .' '  •  • 

. Hendricks  Co.,  Ind . 

. Potter  Co.,  Pa . 


Note 


-(I) 

(2) 


About  8  per  cent  moisture. 

About  12  or  15  per  cent  moisture. 


XT - ,  ^ - llCctlHlg  uy  m 

North  Central  States. 

(3)  Average  green  material. 


Pounds  per  cubic  foot 

27 

28 

46 

38 

39 

45 

34 

36 

53 

34 

35 

52 

39 

41 

46 

38 

39 

47 

40 

42 

49 

37 

39 

46 

36 

37 

46 

41 

42 

47 

4t 

44 

51 

37 

38 

46 

26 

26 

27 

27 

47 

43 

26 

27 

41 

24 

25 

41 

43 

45 

56 

41 

43 

54 

Average  condition 
id  from  precipitation. 

586  MODERN  PULP  AND  PAPER  MAKING 


Species  and  Locality 


Weights 


Kiln-dry  Air-dry  Green 


Deciduous 

Birch,  paper . Rusk  Co.,  Wis . 

“  sweet . Potter  Co.,  Pa . 

“  yellow . Potter  Co.,  Pa . 

“  “  . Marathon  Co.,  Wis . 

Buckeye,  yellow . Sevier  Co.,  Tenn . 

Buckthorn,  cascara . Lane  Co.,  Oregon. ...... 

Butternut . Sauk  Co.,  Wis . 

“  . Sevier  Co.,  Tenn . 

Cherry,  black . Potter  Co.,  Pa . 

“  wild  red . Sevier  Co.,  Tenn . 

Chestnut . Baltimore  Co.,  Md . 

“  . Sevier  Co.,  Tenn . 

Chinquapin,  western . Lane  Co.,  Oregon . 

Cottonwood . Pemiscot  Co.,  Mo . 

“  black . Snohomish  Co.,  Wash . . . 

Cucumber  tree . Sevier  Co.,  Tenn . 

Dogwood  (flowering) . Sevier  Co.,  Tenn . 

“  western . Lane  Co.,  Oregon . 

Elder,  pale . Douglas  Co.,  Oregon - 

Elm,  cork . Marathon  Co.,  Wis . 

“  “  . Rusk  Co.,  Wis . 

“  slippery . Hendricks  Co.,  Ind . 

“  “  . Sauk  Qo.,  Wis . 

“  white . Potter  Co.,  Pa . 

“  “  . Marathon  Co.,  Wis . 

Greenheart . S.  A . 

Gum,  black . Sevier  Co.,  Tenn . 

“  blue . Alameda  Co.,  Cal . 

“  red . New  Madrid  Co.,  Mo . . . 

“  “  . .  . . , . Pemiscot  Co.,  Mo . 

Blackberry . Hendricks  Co.,  Ind . 

“  . Sauk  Co.,  Wis . 

Haw,  pear . Sauk  Co.,  Wis . 

Hickory,  big  shellbark.  .  .  .Sardis,  Miss.  .  . . 

,  “  “  “  . Napoleon,  Ohio . 

“  bittemut . Napoleon,  Ohio . 

“  mockernut . Sardis,  Miss . 

“  “  . Chester  Co.,  Pa . 

1“  “  . Webster  Co.,  W.  Va _ 

“  nutmeg . Sardis,  Miss . 

“  pignut . Sardis,  Miss . 

“  “  . Napoleon,  Ohio . 

“  “  . Chester  Co.,  Pa . 

“  “  . Webster  Co.,  W.  Va.  .. . 

“  Shagbark . Sardis,  Miss . 

“  “  . Napoleon,  Ohio . 

“  “  . Chester  Co.,  Pa . '. 

“  “  . Webster  Co.,  W.  Va _ 

“  water . Sardis,  Miss . 

Holly,  American . Sevier  Co.,  Tenn . 

Hornbean . Rusk  Co.,  Wis . 

Laurel,  California . Douglas  Co.,  Oregon . . .  . 

“  mountain . Sevier  Co.,  Tenn . 

Locust,  black . Sevier  Co.,  Tenn . 

“  honey . Hendricks  Co.,  Ind . 

“  “  . Pemiscot  Co.,  Mo . 


Pounds  per  cubic  foot 


37 

38 

51 

45 

47 

59 

43 

45 

56 

43 

44 

59 

24 

25 

49 

35 

36 

50 

25 

26 

45 

27 

28 

47 

34 

36 

46 

27 

28 

33 

29 

30 

53 

29 

30 

56 

31 

32 

61 

28 

29 

49 

23 

24 

46 

33 

34 

50 

52 

34 

65 

45 

47 

55 

36 

37 

65 

43 

44 

53 

43 

45 

53 

42 

43 

53 

36 

37 

56 

33 

35 

53 

32 

33 

45 

60 

62 

72 

35 

36 

45 

52 

54 

70 

35 

46 

34 

36 

54 

38 

39 

47 

36 

38 

51 

47 

49 

63 

47 

49 

62 

55 

57 

65 

47 

49 

64 

47 

49 

62 

53 

55 

65 

.  . 

.  . 

62 

42 

43 

61 

48 

50 

62 

51 

53 

64 

52 

54 

65 

55 

57  ' 

63 

47 

49 

63 

51 

54 

64 

45 

47 

63 

50 

52 

65 

44 

46 

69 

39 

40 

57 

35 

36 

60 

38 

39 

54 

47 

49 

62 

48 

49 

58 

49 

51 

65 

42 

44 

60 

AMERICAN  PULPWOODS 


587 


Species  and  Locality 


,  Deciduous 

Madrona . Butte  Co.,  Cal . 

. Douglas  Co.,  Oregon . . 

Maple,  Oregon . Snohomish  Co.,  Wash 

red . Marathon  Co.,  Wis .  .  . 

“  . Potter  Co.,  Pa . 

silver . Sauk  Co.,  Wis . 

sugar . Hendricks  Co.,  Ind.  . . 

. Potter  Co.,  Pa . 

. Marathon  Co.,  Wis,  .  . 

Magnolia  (evergreen) . Winn  Parish,  La . 

Oak,  bar . Sauk  Co.,  Wis . 

“  California  black . Butte  Co.,  Cal . 

. Douglas  Co.,  Oregon. . 

“  canyon  live . Butte  Co.,  Cal . 

“  chestnut . .  Sevier  Co.,  Tenn . 

“  cow . Winn  Parish,  La . 

“  laurel . Winn  Parish,  La . 

“  Pacific  post . Douglas  Co.,  Oregon . . 

“  post . Stone  Co.,  Ark . 

“  “  . .'.....  .Winn  Parish,  La . 

red . Stone  Co.,  Ark . 

. Hendricks  Co.,  Ind.  . . 

“  “  . Richland  Parish,  La.  .  , 

. Sevier  Co.,  Tenn . 

“  Spanish  (lowland) .  .  .Winn  Parish,  La . 

“  I  “  (highland)  ...Winn  Parish,  La . . 

“  swamp  white . Hendricks  Co.,  Ind _ 

Oak,  tanbark . Willits,  Cal . 

Oak,  water . Winn  Parish,  La . 

“  white . Stone  Co.,  Ark . :  . 

. Hendricks  Co.,  Ind ...  . 

**  “  . Richland  Parish,  La.  .  . 

. Winn  Parish,  La . 

“  willow . Winn  Parish,  La . 

“  yellow . .  Stone  Co.,  Ark . 

“  “  . Marathon  Co.,  Wis.  ..  . 

Osage  orange . Morgan  Co.,  Ind . 

Pecan  (hickory) . Pemiscot  Co.,  Mo . 

Persimmon . Pemiscot  Co.,  Mo . 

Rhododendron,  great . Sevier  Co.,  Tenn . '. 

Sassafras . Sevier  Co.,  Tenn . 

Serviceberry . Sevier  Co.,  Tenn . 

Silverbell  tree . Sevier  Co.,  Tenn . 

Sour  wood . Sevier  Co.,  Tenn . 

Sugarberry . Pemiscot  Co.,  Mo . 

Sumach,  staghorn . Sauk  Co.,  Wis . 

Sycamore . Hendricks  Co.,  Ind _ 

. Sevier  Co.,  Tenn . 

Tulip  tree . Sevier  Co.,  Tenn . 

Tupelo . St.  John  the  Baptist 

Parish,  La . 

Umbrella,  Fraser . Sevier  Co.,  Tenn . 

Walnut,  black . Kentucky . 

Willow,  western  black . Douglas  Co.,  Oregon .' . . 

“  black . . . vSaukCo.,  Wis . 

“  “  . Pemiscot  Co.,  Mo . 

Witch  hazel . Sevier  Co.,  Tenn . 


W  eights 


Kiln-dry 

Air-dry 

Green 

Pounds  per  cubic  foot 

42 

43 

66 

46 

48 

59 

32 

34 

47 

37 

38 

54 

34 

36 

49 

32 

34 

46 

41 

43 

54 

42 

44 

58 

42 

44 

56 

34 

35 

62 

43  . 

45 

61 

37 

38 

64 

39 

40 

68 

54 

56 

71 

45 

46 

62 

48 

50  , 

65 

45 

47 

65 

48 

50 

69 

46 

47 

60 

47 

49 

66 

43 

45 

65 

42 

44 

64 

48 

50 

67 

41 

42 

61 

47 

49 

67 

40 

42 

62 

50 

52 

69 

43 

44 

66 

43 

45 

63 

44 

46 

59 

46 

47 

61 

46 

48 

57 

45 

47 

63 

43 

46 

67 

43 

43 

63 

40 

42 

62 

54 

56 

62 

45 

47 

61 

51 

53 

63 

39 

40 

62 

31 

32 

44 

52 

54 

6r 

31 

32 

44 

39 

40 

53 

35 

36 

46 

32 

34 

61 

34 

35 

61 

35 

36 

53 

27 

28 

59 

35 

37 

66 

30 

31 

47 

37 

39 

52 

30 

31 

51 

25 

26 

,si 

26 

27 

47 

45 

46 

59 

588  MODERN  PULP  AND  PAPER  MAKING 

Weights 

Species  and  Locality  Kiln-dry  Air-dry  Green 


CONIFERS 


Pounds  per  cubic  foot 


black . 


Lane  Co.,  Oregon . 

23 

24 

49 

Weed,  Cal . 

.  . 

.  . 

41 

Douglas  Co.,  Oregon .... 

30 

31 

39 

Missoula  Co.,  Mont.  .  .  . 

21 

22 

24 

Snohomish  Co.,  Wash . . . 

23 

24 

30 

Shawano  Co.,  Wis . 

21 

21 

28 

Pemiscot  Co.,  Mo . 

28 

29 

47 

St.  John  the  Baptist 
Parish,  La . 

33 

34 

51 

Lane  Co.,  Oregon . 

28 

29 

53 

Plumas  Co.,  Cal . 

30 

31 

40 

Humboldt  Co.,  Cal . 

32 

33 

40 

Johnson  Co.,  Wyo . 

31 

32 

34 

Lane  Co.,  Oregon . 

35 

36 

39 

Chehalis  Co.,  Wash . 

31 

32 

36 

.Lewis  Co.,  Wash . 

35 

37 

41 

Washington  and  Oregon . 

.  . 

37 

.Missoula  Co.,  Mont.  .  .  . 

28 

29 

33 

Deer,  Ore . 

.  . 

53 

Snohomish  Co.,  Wash. . . 

26 

27 

36 

Grand  Co.,  Colo . 

22 

23 

28 

Rusk  Co.,  Wis . 

24 

25 

45 

•  Missoula  Co.,  Mont.  .  .  . 

28 

29 

37 

,  Douglas  Co.,  Oregon .... 

26 

27 

52 

.Multnomah  Co.,  Oregon. 

27 

28 

31 

.Madera  Co.,  Cal . 

25 

26 

.  56 

.Sevier  Co.,  Tenn . 

31 

32 

46 

.Marathon  Co.,  Wis . 

24 

25 

49 

.Missoula  Co.,  Mont.  .  .  . 

30 

32 

45 

.Chehalis  Co.,  Wash . 

28 

29 

41 

Gray’s  Harbor  &  Buckley, 
Wash . 

30 

31 

40 

.Missoula  Co.,  Mont.  .  .  . 

37 

39 

51 

.Stevens  Co.,  Wash . 

33 

34 

42 

.  Nassau  Co.,  Fla . 

43 

45 

53 

.Barron  Co.,  Wis . 

29 

30 

50 

.Plumas  Co.,  Cal . 

27 

28 

47 

.Nassau  Co.,  Fla . 

37 

39 

54 

.Grand  Co.,  Colo . 

27 

28 

33 

.Gallatin  Co.,  Mont . 

27 

28 

47 

.Granite  Co.,  Mont . 

29 

30 

41 

.Jefferson  Co.,  Mont . 

28 

29 

39 

.  Johnson  Co.,  Wvo . 

27 

28 

37 

.  Nassau  Co..  Fla . 

43 

44 

51 

.  Bogalusa,  La . 

41 

42 

56 

.  Lake  Charles,  La . 

42 

43 

45 

.  Tangipahoa  Parish,  La . . 

39 

41 

54 

.Hattiesburg,  Miss . 

38 

40 

42 

.  Sevier  Co.,  Tenn . 

35 

36 

54 

.  Nassau  Co.,  Fla . 

38 

40 

49 

.Shawano  Co.,  Wis . 

32  • 

34 

42 

.Malvern,  Ark . 

35 

36 

45 

.  Bogalusa,  La . 

38 

39 

56 

.  Madera  Co.,  Cal . 

25 

27 

50 

sugar 


AMERICAN  PULPIVOODS 


589 


Weights 


Species  and  Locality 


Kiln-dry  Air-dry  Green 


Conifers 

Pine,  Table-Mountain . Sevier  Co.,  Tenn . 

“  western  white . Missoula  Co.,  Mont.  .  .  . 

“  yellow . Coconino  Co.,  Arizona . .  . 

“  “  “  . Madera  Co.,  Cal . 

“  “  “  . Douglas  Co.,  Colo . 

“  . Stevens  Co.,  Wash . 

“  . Missoula  Co.,  Mont.  .  .  . 

white . Shawano  Co.,  Wis . 

Redwood . Humboldt  Co.,  Cal . 

. Mendocino  Co.,  Cal.  .  .  . 

Spruce,  Engelmann . San  Miguel  Co.,  Colo.  .  . 

, . Grand  Co.,  Colo . 

“  red . CoosCo.,  N.  H . 

“  . Sevier  Co.,  Tenn . 

“  Sitka . Chehalis  Co.,  Wash . 

"  white . .* . Coos  Co.,  N.  H . 

“  “  . Rusk  Co.,  Wis . 

Tamarack . Shawano  Co.,  Wis . 

Yew,  western . Snohomish  Co.,  Wash. . . 


Pounds  per  cubic  foot 

36 

37 

54 

29 

30 

59 

25 

26 

44 

28 

29 

53 

28 

29 

49 

.  . 

36 

27 

28 

51 

26 

27 

39 

23 

24 

36 

26 

27 

39 

22 

23 

48 

24 

25 

30 

28 

29 

32 

27 

28 

35 

25 

26 

33 

25 

26 

28 

29 

30 

35 

37 

38 

47 

43 

45 

54 

590  MODERN  PULP  AND  PAPER  MAKING 


TABLE  FOR  COMPARING  DIFFERENT  SYSTEMS  OF  ALKALIM¬ 
ETRY  FOR  CAUSTIC  SODA 


Caustic  Soda  is  sold  on  its  strength  in  Na20,  as  indicated  in  the  New  York 
and  Liverpool  Test  column  below. 

•  The  price  is  always  based  on  6o%  Caustic,  with  a  proportionate  addition 
for  the  higher  percentages. 


No.  I 


Caustic  Soda 
Sodium  Hydrate 
NaOH 
Per  Cent 


74  83 

75-48 

76. 12 
76.77 
77-40 

78.05 

78.70 

79-35 

80.00 

80.65 

81 .29 

81.94 
82.58 

83-23 

83.87 

84.52 
85.16 
85.81 
86.45 
87. 10 

87.74 

88.39 

89.03 

89.67 

90.30 

90.95 

91.60 

92.25 

92.90 

93- 55 

94.19 

94- 84 

95- 48 

96.13 

96.77 

97-32 

98.06 

98.71 

99.35 

100.00 


No.  2 


Actual  Alkali 
Sodium  Oxide 
NaaO 
Per  Cent 


58.0 

58.5 

59-0 

59-5 

60.0 

60.5 
61 .0 

61.5 
62.0 

62.5 

63.0 

63- 5 

64.0 

64- 5 

65.0 

65.5 

66.0 

66.5 
67.0 

67-5 

68.0 

68.5 
69.0 

69-5 

70.0 

70.5 

71 .0 
71-5 
72.0 

72.5 

73- 0 
73  -  5 
74.0 

74- 5 

75- 0 

75-5 

76.0 

76.5 

77-0 

77-5  • 


No.  3 

Newcastle  Test 
Sodium  Oxide 
NaaO 
Per  Cent 


58.76 

59-27 

59-77 

60.28 

60.79 

61.30 

61 . 80 

62.31 

62 . 82 

63- 32 

63.83 

64- 33 

64.84 

65.35 

65- 85 

66.36 

66.87 

67-37 

67.88 

68.39 

68.89 

69.40 

69.91 

70.41 

70.92 

71-43 

71-93 

72.44 

72.95 

73-45 

73- 96 

74- 47 

74- 97 

75- 48 

75-99 

76.49 

77.00 

77-51 

78.01 

78.52 


No.  4 


N.  Y.  &  Liv. 
Sodium  Oxide 
NaaO 
Per  Cent 


59.87 

60.38 

60,90 

61 .42 
61.93 

62.45 

62.97 

63- 48 
64.00 

64- 52 

65- 03 

65-55 

66.06 
66.58 
67. 10 

67.61 
68.13 
68.65 
69. 16 
69.68 

70.19 

70.71 

71.23 

71-74 

72.26 

72.77 

73.29 

73- 81 

74- 32 

74- 84 

75.35 

75- 87 
76.39 
76.90 
77.42 

77-94 

78.45 

78.97 

79-49 

80.00 


AMERICAN  rULPWOODS 


59 1 


TABLE  FOR  COMPARING  DIFFERENT  SYSTEMS  OF  ALKALIM¬ 
ETRY  FOR  SODA  ASH 

The  following  table  gives  the  chemical  and  commercial  equivalents  for  the 
different  kinds  of  alkali.  On  the  continent  of  Europe,  alkali  is  sold  by  its 
strength  in  carbonate  of  soda  (Na2C03),  as  per  column  No.  i  of  table-  In 
England,  alkali  is  sold  nominally  on  its  strength  in  actual  alkali  (Na20),  as 
per  column  No.  2  of  table,  but  actually  on  the  so-called  “Newcastle  Test”  of 
the  actual  alkali,  as  per  column  No.  3  of  table.  In  the  United  States,  the 
commercial  standard  for  75  years  has  been  the  New  York  and  Liverpool  Test 
for  actual  alkali,  as  per  column  No.  4  of  table. 


No.  I 

No.  2 

No.  3 

No.  4 

Soda  Ash 

Actual  Alkali 

Newcastle  Test 

N.  Y.  &  Liv. 

Sodium  Carbonate 

Sodium  Oxide 

Sodium  Oxide 

Sodium  Oxide 

Na2C03 

Na20 

Na20 

Na20 

Per  Cent 

Per  Cent 

Per  Cent 

Per  Cent 

79-51 

46-5 

47.11 

48.00 

80.37 

47-0 

47.62 

48.51 

81 .22 

47-5 

48. 12 

49-03 

82.07 

48.0 

48-63 

49-54 

82.93 

48-5 

49.14 

50.06 

83.78 

49  0 

49.64 

50.58 

84.64 

49-5 

50.15 

51-09 

85.48 

50.0 

50.(6 

51.61 

86.34 

50-5 

51.16 

52.12 

87.19 

51.0 

51-67 

52.64 

88.05 

51-5 

52.18 

53  16 

88.90 

52.0 

52.68 

53-67 

89.76 

52-5 

53-19 

54  19 

90.61 

53-0  . 

53-70 

54-70 

91-47 

53-5 

54.20 

55-22 

92.32 

54-0 

54-71 

55.74 

93- 18 

54-5 

55-22 

56.25 

94-03 

55-0 

55-72 

56.77 

94-89 

55-5 

56.23 

57.29 

95-74 

56.0 

56.74 

57.80 

96.60 

56.5 

57-24 

58.32 

97-45 

57-0 

57-25 

58.83 

98-31 

57-5 

58.26 

59-35 

99.16 

58.0 

58.76 

59-87 

100.00 

58.5 

59-27 

60.38 

t 


\ 


INDEX 


Absorption  of  SO2,  equipment,  134 
Acid,  recovery  system,  142 
Acid,  sulphate  process,  chemistry, 
126 

strength  advisable,  140 
Acid  plant,  sulphite  process,  126, 
Acid  resisting  material,  126 
Acid  room,  record,  467 
Acidity,  boiler  feed  water,  409 
Agalite,  241 
Agave,  24 

Air,  to  burn  sulphur  to  SO2,  132 
Air,  moisture  content,  403 
Alum,  247 

amount  required,  251 
analyses,  248 
function,  248 
hardening  effect,  249 
Alumina,  in  clay,  determination, 
237 

Animal  size,  242 
Antichlor,  216 

Apron,  Fourdrinier  machine,  294, 

348 

specifications,  359 
Aspen,  II 

Auxiliaries,  steam  plant,  429 
Backfall,  in  beater,  225 
Bag,  paper,  48 
Bagasse,  31 
Balanced  draft,  433 
Balanced  draft  gauge,  436 
Balsam,  8 

cellulose  percentage,  6 
Bamboo,  22 
Bark  removal,  77 
Barker,  82 

refuse,  value  as  fuel,  428 
Barker  milk-of-lime  system,  135 
Barking  drum,  81 
Beater,  221 
capacity,  222 
Claflin  continuous,  266 
continuous,  265 
dimensions,  222 
emptying,  225 
function,  226 
Miller  duplex,  263 
specifications,  271' 

Umpherston,  265 


Beater  knives,  268 
Beater  roll,  268 
bandless,  269 

Beater  room,  equipment,  mainte¬ 
nance,  268 
record,  471 
Beating,  221 
Bed-plate,  beater,  270 
Bellmer  bleaching  process,  210 
Beech,  cellulose  percentage,  6 
Belts,  395^ 

Bennett  Felt  Cleanser,  325 
Birch,  cellulose  percentage,  6 
Bird  continuous  beater  attachment, 
266 

Bird  inward  flow  rotary  screen,  289 
“Black  ash,”  154 
causticizing,  160 
loss  from  rotaries,  175 
loss  in  stack,  determination, 

174 

recovery  from  stack,  172 
Bleach  room,  ventilation,  402 
Bleaching,  202,  207 
acid,  217 

continuous  system,  21 1 
electrolytic,  217 
ground  wood,  217 
hot,  215 

Bleaching  liquor,  amount  required, 

215 

preparation,  205 
testing,  206 

Bleaching  powder,  203 
deterioration,  204 
Blotting  paper,  50 
Blow-pipe,  sulphite  digester,  104 
Blow  pit.  III 
Boiler,  auxiliaries,  429 
capacity  required,  428 
foaming,  409 
rags,  28,  29 

rating  for  heating  surface,  424 
straw,  20 

Boiler  feed  pumps,  431 
Boiler  feed  regulator,  432 
Boiler  plant,  41 1 
Boiler  pressure,  chart,  455 
Boiler  room,  dimensions  per  ton 
paper,  428 


593 


594 


INDEX 


Boiling,  rags,  27 
straw,  21 
Book  paper,  40 
grades,  43 

“Breaking  up”  engine,  waste  paper, 

38 

Breaks,  causes,  349 
Breast  roll,  Fourdrinier  machine, 
349. 

Bronze  pipe,  use  of,  391 

Building  paper,  53 

Bundle  finishing,  382 

Burgess  milk-of-lime  system,  135 

Burring,  188 

Burrs,  189 

“Butchers”  paper,  45 

Canadian  woods,  composition,  6 
CO2  recorder,  415 
Calcium  oxide,  in  clay,  determina¬ 
tion,  238 

Calender.  See  also  Super-calender 
Calender  doctor,  336 
Calender  rolls,  335 
specifications,  367,  373 
Camel  hair  belting,  396 
Car  loading,  387 

Carlson  and  Waerh  evaporator,  157 
Cast  iron  pipe,  use  of,  390 
Causticizing,  160 
Dorr  system,  161 

Causticizing  systems,  efficiency,  168 
Cellulose,  5 

Cement,  digester  lining,  loi 
Chain,  log  haul,  55 
Chain,  slasher,  59 
Chemical  control,  importance  of, 
sulphate  process,  183 
value,  458 

Chestnut,  cellulose  percentage,  6 
Chip  bin,  92 
Chip  conveyor,  93 
Chip  inspection,  94 
Chip  screen,  89 
Chipper,  85 
efficiency,  465 

Chlorine,  available  in  bleaching 
powder,  corresponding  to 
.French  degrees,  204 
liquid,  for  bleaching,  206 
Cigarette  paper,  46 
Claflin  continuous  beater,  266 
Clay,  231 

American  versus  British,  233 
analyses,  232,  233,  237 
Canadian,  analysis,  235 
preparation,  233 
production  in  tj.  S.,  233 
retention,  23.S,  239 
Closed  loop  boiler  feed  system,  439 


Coal,  419 

Coal  bunker,  capacity  per  ton  pa¬ 
per,  428 
Coating,  41 

Coating  mill,  interior  view,  42 
Color,  253 
Conveyor,  chip,  93 
wood  storage,  73 
Cooking,  Morterud  process,  no 
soda  process,  148 
American  practice,  150-153 
sulphate  process,  177 
sulphite,  105 
pressure,  107 
relieving,  108 
temperature,  108 
Cooler,  sulphur  dioxide,  132 
Cord,  pulpwood,  weight,  79 
Cotton  wool,  analysis,  5 
Cottrell  electrical  precipitation 
“black  ash”  recovery,  173 
Couch  rolls,  Fourdrinier  machine, 
306,  350 

specifications,  360,  374 
suction,  31 1 

Couch  roll  jacket,  307,  308,  351 

Crown  filler,  241 

Crusher,  88 

Cutlery  paper,  45 

Cutting  rags,  26 

Cylinder  machine,  340 

Dandy  roll,  Fourdrinier  machine, 
304,  351 

specifications,  361,  373 
Decker,  121 

Deckered  stock  chest,  122 
Deckle  straps,  Fourdrinier  machine, 
302,  350 

specifications,  361,  372 
De-fibering,  waste  paper,  Winestock 
process,  36 

De-inking,  waste  paper,  35 
Winestock  process,  36 
Diaphragm  screen,  282 
Digester,  chip  capacity,  106 
operation,  effect  on  steam  plant, 

414 

power  required,  429 
soda  process,  146 
straw,  20,  22 
sulphate  process,  177 
sulphite  process,  97 
filling,  106 
heating,  106 
rotary,  no 
steam  supply,  103 
welded,  147 

Direct  cooking,  sulphite,  105 
Disc  evaporators,  157 
Doctor,  in  beater,  225 


INDEX 


Dolomite,  for  sulphite  process,  129, 

Dorr  causticizing  system,  161 
flow  sheet,  166 
Draft,  balanced,  432 

forced,  equipment  for,  426 
Draft  recording  gauge,  436 
Drip  systems,  steam  mains,  439 
Drive,  .Fourdrinier  machine,  343, 

446 

specifications,  369 
Dryer,  arrangement,  327 
heating,  328 
specifications,  364,  374 
water  removal,  328 
Dryer  cylinders,  326 
Dryer  felt,  317,  330 
care,  321,  322 
mending,  324 
replacing,  331 
seam,  332 
washing,  325 

Dryer  felt.  See  also  Wet  felt. 
Dryer  felt  roll,  334 
specifications,  367 
Dryer  gears,  335 
Dusting,  rags,  25 
Dyestuffs,  254 

Ebony,  cellulose  percentage,  6 
Electric  drive,  beater  room,  267 
Fourdrinier  machine,  446 
Emptying  valve,  beater,  225 
Enclosed  loop  trap  system,  steam 
mains,  439 

Engine,  Beater.  See  Beater 
Esparto,  ii 
analyses,  ii 
cellulose  percentage,  6 
Evaporator,  Carlson  and  Waern, 

157 

disc,  157 

multiple  effect,  soda  process,  154 
Yaryan,  157 

Farnsworth  system,  steam  distribu¬ 
tion,  440 

Feed  chains,  slasher,  59 
Feed  water,  purification,  407 
Feed  water  regulator,  432 
Felt,  dryer.  See  Dryer  felt 
Felt,  papermakers’.  See  Dryer  felt; 
Wet  felt 

Felt,  wet.  See  Wet  felt 
Fibre,  varieties,  8 
vulcanized,  49 
Filler,  231 
Filter  paper,  51 

Filtration,  causticizing  soda  ash,  161 
water,  353,  406 
Finish,  machine,  43 
Finishing  room,  378 


595 

Fire  protection,  water  supply  for, 
410 

wood  pile,  74 

Flax,  cellulose,  percentage,  6 
Flax  fibre,  waste,  32 
Flow  box.  See  Head  box 
Flue  gas  analysis,  CO2  recorder,  415 
Orsat  apparatus,  415 
Flue  temperature  recorder,  436 
Fly-bar,  268 
Foaming,  boiler,  409 
Forced  draft,  equipment  for,  426 
Fourdrinier  machine,  281. 
drive,  343,  446 
friction  load,  450 
specifications,  358 
starting,  345 
Fourdrinier  wire,  296 
deterioration,  298 
loads,  450 

putting  on  machine,  300,  350 
starting,  301 

Friction  loaa,  Fourdrinier  machine, 

450 

Fuel,  steam  plant,  419 

Furnace,  rotary,  soda  recovery,  is8 

“Furnish,”  224 

Gas,  natural,  fuel,  420 

Gas  analysis,  Orsat  apparatus,  415 

Gauges,  435 

Grinder,  pressure  regulation,  193 
specifications,  199 
Ground  wood,  i,  184 
bleaching,  217 
quality,  determination,  198 
Ground  wood  mill,  184 
Guard  board,  couch  rolls,  308 
specifications,  360 

Guide  roll,  automatic,  for  Fourdri¬ 
nier  wire,  specifications,  359, 
372 

dryer  felt,  333 
“Gypsum,”  134 

Gypsum,  ground,  as  filler,  241 

“Half  stuff,”  30 
Hangings,  52 

Harper  Fourdrinier  machine,  341 
Head,  sulphite  digester,  103 
Head  box,  Fourdrinier  machine, 
293,  348 

specifications,  359,  372 
Heat  conservation,  453 
Heating  system,  453 
Hemlock,  ii 

Hemlock,  cellulose  percentage,  6 
Hemp,  Italian,  23 
Manila,  23 

cellulose  percentage,  6 
Sunn,  23 


596 


INDEX 


Herreshoff  pyrites  furnace,  144 
Hollander,  30,  31,  208,  223 
Holly  drip  system,  439 
Horsepower,  boiler,_  definition,  424 
Hosing,  blow  pit,  112 

Intermediate  tank,  112 
Iron,  in  clay,  determination,  237, 
238 

Jenssen  system,  SO2  absorption,  136 
Jordan  engine,  261 
maintenance,  270 
power  requirement,  261 
split  shell,  262 
Jute,  23 

cellulose  percentage,  6,  23 
Kaolin,  231; 

Knives,  barking  machine,  care,  83 
Knotter  screen,  113 
Kraft  paper,  3,  44,  176 

Labor  requirement,  slasher,  60 
Laps,  123 

reason  for  making,  121 
“Lay-boy,”  384 
Lead  pipe,  use  of,  391 
Lead  digester  lining,  disadvan¬ 
tages,  lOI 

Leather,  best  belt  material,  395 
Lenix  idler  pulley,  398 
Lighting,  404 
Limestone,  128 

Linden,  cellulose  percentage,  6 

Linen,  cellulose  percentage,  6 

Linen  finish,  44 

Lining,  digester,  loi 

Load,  Fourdrinier  machine,  450 

Log  counters,  55 

Log  haul  up,  54 

Log  kicker,  56 

Log  splitter,  67 

Machine  room,  281 
Manila.  See  Hemp,  Manila 
Manila  wrapping  paper,  45 
Marshall  engine,  263 
Matherkier,  30 
Mid  feather,  beater,  223 
Milk-of-lime  system,  SO2  absorp¬ 
tion,  133,  135 
power  requirement,  140 
versus  tower  system,  138 
Miller  duplex  beater,  263 
Mills,  paper  and  pulp,  number  in 
U.  S.  A.,  1918,  40 
Mitscherlick  process,  sulphite.  T05 
Morterud  sulphate  process,  177 
Morterud  sulphite  process,  no 
Mullen  paper  tester,  462 


Natural  gas,  420 

Newspapers,  American,  statistics, 

50 

Newsprint,  50 

acid  strength  required, '  sulphite 
process,  141 
sizing  of,  246 

Oil  fuel,  420 
Orsat  apparatus,  415 
weight  percentage  calculation, 

417 

Paper,  bag,  48 
blotting,  50 
book,  40 
book,  grades,  43 
cigarette,  46 
coated,  41 
cutlery,  45 
exports,  1918,  40 
filter,  51 
imports,  1918,  40 
Manila,  45 
machine  finish,  43 
newsprint,  50 
parchment,  49 

production  in  U.  S.  A.,  1918,  40 

roofing,  53 

testing,  458,  461 

tissue,  46 

varieties,  40 

wall,  52 

waste.  See  Waste  paper 
wrapping,  44 
“Butchers,”  45 
Kraft,  44 
Manila,  45 
writing,  40,  43 
rag  stock  for,  24 

Paper  and  pulp  mills,  number  in 
U.  S.  A.,  1918,  40 
Paper  making  machine.  See  Four¬ 
drinier  machine ;  Cylinder 
machine ;  Harper  Fourdrinier 
machine 

“Paper  stock,”  defined,  24 
Parchment  paper,  49 
Pearl  hardening,  241 
Pigments.  254 

Pine,  Jack,  cellulose  percentage,  6 
Scotch,  cellulose  percentage,  6 
yellow,  12 
Pipe  covering,  445 
Piping,  390 

Plate,  diaphragm  screen,  285 
Plant,  arrangement  of  buildings, 
.389 

design,  general  considerations. 
.388 

lighting,  404 


INDEX  597 


Plant,  location,  388 
steam  supply,  389 
ventilation,  400 
water  supply,  406 
“Pocher,”  208 
Pony  dryer,  334 
Poplar,  II 

cellulose  percentage,  6 
Power,  ground  wood  mill,  184 
Power  plant,  41 1 
Power  requirement,  456 
acid  pump  for  digester,  106 
agitator  in  intermediate  tank, 
112 

centrifugal  screen,  118 
chip  conveyor,  93 
chipper,  88 

ground  wood  mill  water  supply, 
188 

ground  wood  mill,  per  ton  pulp, 
192 

Jordan  engine,  261 
knotter  screen,  114 
log  splitter,  68 
milk-of-lime  system,  140 
pulp  grinder,  187 
re-chipper,  92 
slasher,  60 
stock  pump,  187 
stock  pump  to  beater,  259 
sulphite  digester,  104 
tower  system,  140 
tumbling  drum,  82 
Power  yield,  refuse  from  barker 
as  fuel,  428 

Press  rolls,  Fourdrinier  machine, 
308 

crowning,  310 
specifications,  363,  374 
suction,  314 

Press  room,  record,  469 
Pressure,  grinder,  190 
Pressure  versus  vacuum,  acid  ab¬ 
sorption  systems,  143 
Pressure  gauge,  boiler,  430,  435 
Pressure  regulator,  electric,  for 
grinder,  193 
Pulleys,  idler,  398 
Pulp,  bleaching,  202 
chemical,  I 
Kraft  process,  3 
manufacture,  i 
materials,  5 

mechanical.  See  Ground  wood 
soda  process,  3 
straw,  manufacture,  20 
strawboard,  manufacture,  21 
sulphate  process,  3 
sulphite  process,  2 
yield  from  various  materials,  7 
Pulp  grinder,  186 


Pulp  stone,  speed,  effect  on  prod¬ 
uct,  191 

Pulp  thickener ;  ground  wood  mill, 

12 1,  187 

Pulpwood.  See  Wood 
Pump,  393 
boiler  feed,  431 

boiler  feed,  piston  speed,  432 
turbine-driven,  specifications,  431 
Pyrites  burning,  143 
Pyrites  burning,  costs,  145 

Rags,  24 
grades,  25 
boiling,  26 
Rag  cutter,  26 
Rail  shipment,  387 
Railroad  facilities,  paper  plant,  390 
Re-chipper,  92 

Recovery  systems,  soda  process, 

.154 

efficiency,  170 
sulphate  process,  180 
Recovery  tower,  142 
Reel,  337 
specifications,  368 
Relieving,  sulphite  digester,  108 
Return  wire  roll,  Fourdrinier  .  ma¬ 
chine,  specifications,  359 
Rewinding,  379 
Riffler,  114 
Riffier  pump,  114 
Roll,  finishing,  378 
Roll-bars,  268 
Roofing  paper,  53 
Rope  drive,  399 
Rosin  size,  242 
varieties,  245 
Rubber  belting,  395 

Sand  trap,  in  beater,  224 
Jordan  engine,  262 
Sandberg  cooler,  133 
Satin  white,  241 
Save-all,  353 

Save-all  box,  Fourdrinier  machine, 
specifications,  362,  364 
Saw._  57 
adjustment,  66 
care  of,  63 
collars  for,  66 
speed,  66 

Saw  frame,  construction,  65 
Saw  mill,  54 
construction,  65 
Schopper  paper  tester,  462 
Schweitzer’s  reagent,  5 
Score  cutter,  380 
Screen.  117,  282,  348 
centrifugal,  117 
cleaning,  118 


598 


INDEX 


Screen,  installation,  120 
, chip,  89 
diaphragm,  282 
rotary,  289 

Screen  plate,  screwless,  288 
Screen  plate  fastener,  287 
Screen  room,  record,  468 
Screenings  chest,  119 
Screenings  grinder,  119 
Screenings  press,  119 
Seam,  dryer  felt,  332 
Settling  tank  save-all,  354 
Shake,  Fourdrinier  machine,  speci¬ 
fications,  362 

Shake  rail,  specifications,  361 
Shaker  chip  screen,  91 
Sheet  cutter,  383 
Shipment,  387 

Showers,  Fourdrinier  machine, 
specifications,  362 

Silica,  in  clay,  determination,  237 
Silicate  of  soda,  252 
Sizing,  241,  245 
Slasher,  57 
labor  required,  60 
performance,  60 
power  requirement,  60 
Slasher  chain,  59 

Slices,  apron,  Fourdrinier  machine, 
294 

“Slip,”  strength  of,  234 
Slitter,  339 
specifications,  368 
Slitting,  379 
Sliver  screen,  187 

Smith  forced  draft  equipment,  426 
Smoothing  press  rolls,  Fourdrinier 
machine,  314 
Soda  process,  3,  146 
recovery  systems,  154 
recovery  systems,  efficiency,  170 
Softening,  waste  paper,  38 
Soot  blower,  432 
Sorting,  rags,  24 
waste  paper,  33 

Speed,  pulp  stone,  effect  on  prod¬ 
uct,  191 
Splitter,  67 
Spruce,  8 

cellulose  percentage,  6 
Stacker,  wood  storage,  75 
Starch,  253 
Steam,  books  on,  41 1 
distribution  system,  438 
Farnsworth,  439 
flow  meter,  436 
piping  for,  -391 
pressure,  436 
pressure  gauge,  430,  435 
superheated,  sulphite  "  digesters, 
142 


Steam,  use  in  bleaching,  215 
Steam  mains,  438 
repairs,  443 
Steam  plant,  389,  41 1 
Steam  supply,  sulphite  digester,  103 
Stebbins  milk-of-lime  system,  135 
Stock  chest,  257 
Stock  pump,  187 
power  requirement,  259 
Stoker,  automatic,  421 
advantages,  423 
capacity  required,  428 
engine  for  driving,  425 
Storage,  385 
“Strainers,”  282 
Straw,  II,  20 
analyses,  20 

cellulose  percentage,  6,  20 
Strawboard,  manufacture,  21 
String  catcher,  in  beater,  225 
Suction  box,  Fourdrinier  machine, 

304,  351  ’ 

specifications,  361,  373 
Suction  couch  rolls,  Fourdrinier 
machine,  31 1 

Suction  press  rolls,  Fourdrinier 
machine,  314 

Sulphate  liquor,  composition,  176, 
182 

Sulphate  mill,  interior,  178 
Sulphate  process,  3,  176' 

Sulphite  process,  2,  95 
acid  plant,  126 
acid  strength  required,  140 
chemistry,  97 
cooking,  13,  105 
experimental  cooks,  13-19 
Morterud  method,  no 
Sulphur,  127 

per  ton  sulphite  pulp,  142 
Sulphur  burner,  129 
rotary,  130 

Sulphur  dioxide,  absorption,  134 
cornparison  of  systems,  138 
solubility  in  water,  143 
Surge  tank,  on  hydraulic  system, 
ground  wood  mill,  197 
Swing  saw,  62 


Table  rolls,  Fourdrinier  machine, 
303,  349 

specifications,  359 
Talc,  240 

Target,  blow  pit,  in 
Taylor  stoker,  423 
Temperature,  influence  on  quality 
of  ground  wood,  189 
Temperature  recorder,  feed  water, 
.  436 

Testing,  sulphite  process,  109 


INDEX 


599 


Tests,  paper  and  paper  materials, 

458 

recording,  464 

'I'hrasher,  rag  dusting  machine,  25 
Tilghman  patent,  sulphite  process, 
96 

1  issue  paper,  46 

Tower  system,  SO2  absorption,  136 
power  requirement,  140 
,  Towers,  Jenssen,  136 
Tromblee  and  Paul  sulphur  burner, 
130 

Tube  rolls,  Fourdrinier  machine, 
303,  349 

specifications,  359,  372 
Tumbling  drum,  79 
Turbine,  steam,  individual  drive 
for  Fourdrinier  machine,  448 

Umpherston  beater,  265 

Valves,  in  piping  system,  392 
Ventilation,  400 
Venturi  meter,  436 
Vesuvius  sulphur  burner,  13 1 
Vomit  pipe,  blow  pit,  ill 

Wall  paper,  52 
weights,  53 

Walpole  outward  flow  rotary 
screen,  292 

Washing,  in  blow  pit,  112 
rags,  30 

soda  process,  149 
sulphate  process,  180 
Waste  material,  for  paper  stock, 
32 

Waste  paper,  de-inking,  35 
for  paper  stock,  32' 
grades,  33 
re-manufacture,  34 
softening,  38 
sorting,  33 

Water,  purification,  406 
Water  glass,  232 

Water  pipe,  Fourdrinier  machine, 
specifications,  362 

Water  supply,  ground  wood  mill, 
188 


Water  supply,  paper  plant,  406 
Weaving  devices,  348 
Webb  paper  tester,  464 
Wedge  pyrites  furnace,  144 
Wet  felt,  308,  317 
Wet  machine,  123 
“White  liquor.”  See  White  water 
"White  water,”  stock  in,  record,  470 
use,  236 

Widney  paper  testing  machine,  463 
Willesclen  paper,  49 
Willow,  cellulose  percentage,  6 
“Willow,”  rag  dusting  machine,  25 
Winestock  process,  36 
Winder,  339 
specifications,  368 
Wire,  Fourdrinier.  See  Fourdrin¬ 
ier  wire 

Witham  paper  testing  machine,  463 
Witham  screwless  screen  plate 
fastener,  288 

Witham-McEwen  save-all,  355 
Wood,  cellulose  percentage,  5 
consumption,  paper  making,  9-10 
by  States,  1918,  10 
Wood,  ground.  See  Ground  Wood 
Wood,  pulp,  per  ton  paper,  70 
weight  of  cord,  79 
yield  per  tree,  71 
pulp  making  properties,  13-19 
quality,  for  mechanical  pulp,  185 
storage,  72 

protection  from  flood,  389 
varieties  for  various  papers,  8 
Wood  pile,  72 
Wood  pond,  79 
Wood  pulp.  See  Pulp 
Wood  room,  72 
Wrapping,  paper  bundles,  381 
Wrapping  paper,  44 
Writing  paper,  40,  43 


Yankee  machine,  342 
Yaryan  evaporator,  157 


Zeolite  process,  water  purification. 
409 


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>  >333  >>>3)3  3  *  333 

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,  -V' 

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